over to get_thread_recorder() to be agnostic about which thread we're running on

replace llinfos, lldebugs, etc with new LL_INFOS(), LL_DEBUGS(), etc.

fixed ostream precision munging in llsys

various fixes to lltrace
start() on started recording no longer resets
fixed various instances of unit forgetfullness in lltrace
recording split now has gapless timing
scene monitor now guarantees min sample time
renamed a bunch of stats
added names to debug thread view on windows

also, removed LLTrace::init and cleanup
removed derived class implementation of memory stat for LLMemTrackable
is automatic now

removed LLThreadLocalSingleton
collapsed all thread recorder classes to single type, LLTrace::ThreadRecorder
moved fasttimer stack head to llthreadlocalsingletonpointer via ThreadRecorder

pulled swap() out of ui time block
cleaned up internal lltrace dependencies, factored out common accumulator definitions

fixed copy construction behavior of Recordings to not zero out data
split measurement into event and sample, with sample representing
a continuous function

changed thread id declaration to be local to llthread.cpp and use
currentID() uniformly across platforms

fixes to merge

fixed units conversion so that trace getters return convertable units
removed circular dependencies from lltrace*
converted more stats to lltrace

Fix non-thread-safe refcounting of LLHTTPClient::Responder and fix out-of-order deletion of LLTextureFetch on shutdown

renamed LLTrace::ThreadTrace to LLTrace::ThreadRecorder
renamed LLTrace::Sampler to LLTrace::Recording

cleaned up API
samplers are now value types with copy-on-write buffers under the hood
removed coupling with LLThread

created separate constructor for static allocation of sampler buffer
fixed start/stop/resume semantics of samplers and added sampler time interval tracking

slave threads now pushing data to master thread

fixed various issues related to unit tests and LLThreadLocalPtr initialization and teardown

moved LLThread::lockData and unlockData back to header

moved LLThreadLocalPtr to llapr
fixed various startup race conditions for LLThreadLocalPtr

added LLThreadLocalPtr
broke llmutex out into llmutex.h
got primary sampling buffer under thread local storage

LLMutex recursive lock, global & per-request tracing, simple GET request, LLProxy support, HttpOptions starting to work, HTTP resource waiting fixed.
Non-LLThread-based threads need to do some registration or LLMutex locks taken out in these
threads will not work as expected (SH-3154).  We'll get a better solution later, this fixes
some things for now.  Tracing of operations now supported.  Global and per-request (via
HttpOptions) tracing levels of [0..3].  The 2 and 3 levels use libcurl's VERBOSE mode
combined with CURLOPT_DEBUGFUNCTION to stream high levels of detail into the log.  *Very*
laggy but useful.  Simple GET request supported (no Range: header).  Really just a
degenrate case of a ranged get but supplied an API anyway.  Global option to use the
LLProxy interface to setup CURL handles for either socks5 or http proxy usage.  This
isn't really the most encapsulated way to do this but a better solution will have to
come later.  The wantHeaders and tracing options are now supported in HttpOptions giving
per-request controls.  Big refactoring of the HTTP resource waiter in lltexturefetch.
What I was doing before wasn't correct.  Instead, I'm implementing the resource wait
after the Semaphore model (though not using system semaphores).  So instead of having
a sequence like:  SEND_HTTP_REQ -> WAIT_HTTP_RESOURCE -> SEND_HTTP_REQ, we now
do WAIT_HTTP_RESOURCE -> WAIT_HTTP_RESOURCE2 (actual wait) -> SEND_HTTP_REQ.  Works
well but the prioritized filling of the corehttp library needs some performance
work later.

fix for SH-2823 and SH-2824: LLCurl crash inside LLBufferArray::countAfter() and LLBufferArray::copyIntoBuffers

SH-920 Wait for threads to shut down before deleting them -- also, fix some assertions that were encouraging people to comment out the destruction of LLSignal.

accessed through the static LLThread::tldata().
Currently this object contains two (public) thread-local
objects: a LLAPRRootPool and a LLVolatileAPRPool.

The first is the general memory pool used by this thread
(and this thread alone), while the second is intended
for short lived memory allocations (needed for APR).
The advantages of not mixing those two is that the latter
is used most frequently, and as a result of it's nature
can be destroyed and reconstructed on a "regular" basis.

This patch adds LLAPRPool (completely replacing the old one),
which is a wrapper around apr_pool_t* and has complete
thread-safity checking.

Whenever an apr call requires memory for some resource,
a memory pool in the form of an LLAPRPool object can
be created with the same life-time as this resource;
assuring clean up of the memory no sooner, but also
not much later than the life-time of the resource
that needs the memory.

Many, many function calls and constructors had the
pool parameter simply removed (it is no longer the
concern of the developer, if you don't write code
that actually does an libapr call then you are no
longer bothered with memory pools at all).

However, I kept the notion of short-lived and
long-lived allocations alive (see my remark in
the jira here: https://jira.secondlife.com/browse/STORM-864?focusedCommentId=235356&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-235356
which requires that the LLAPRFile API needs
to allow the user to specify how long they
think a file will stay open. By choosing
'short_lived' as default for the constructor
that immediately opens a file, the number of
instances where this needs to be specified is
drastically reduced however (obviously, any
automatic LLAPRFile is short lived).

***

Addressed Boroondas remarks in https://codereview.secondlife.com/r/99/
regarding (doxygen) comments. This patch effectively only changes comments.

Includes some 'merge' stuff that ended up in llvocache.cpp
(while starting as a bug fix, now only resulting in a cleanup).

***

Added comment 'The use of apr_pool_t is OK here'.

Added this comment on every line where apr_pool_t
is correctly being used.

This should make it easier to spot (future) errors
where someone started to use apr_pool_t; you can
just grep all sources for 'apr_pool_t' and immediately
see where it's being used while LLAPRPool should
have been used.

Note that merging this patch is very easy:
If there are no other uses of apr_pool_t in the code
(one grep) and it compiles, then it will work.

***

Second Merge (needed to remove 'delete mCreationMutex'
from LLImageDecodeThread::~LLImageDecodeThread).

***

Added back #include <apr_pools.h>.

Apparently that is needed on libapr version 1.2.8.,
the version used by Linden Lab, for calls to
apr_queue_*. This is a bug in libapr (we also
include <apr_queue.h>, that is fixed in (at least) 1.3.7.

Note that 1.2.8 is VERY old. Even 1.3.x is old.

***

License fixes (GPL -> LGPL). And typo in comments.
Addresses merov's comments on the review board.

***

Added Merov's compile fixes for windows.

Reviewed by Nyx.