The logging subsystem depends on two different LLSingletons for some reason.
It turns out to be very difficult to completely avoid executing any logging
calls after the LLSingletonBase::deleteAll(), but we really don't want to
resurrect those LLSingletons so late in the run for a couple stragglers.
Introduce LLSingleton::wasDeleted() query method, and use it in logging
subsystem to simply bypass last-millisecond logging requests.

SL-409 - added tracking for bytes fetched to viewer assets metrics (does not currently work for textures)

The Visual C++ runtime produces typeid(MyClass).name() as "class MyClass".
It's prudent to check for the presence of that prefix before stripping off the
first six characters, but if the first comparison should ever fail, find()
would continue searching the rest of the string for "class " -- a search
guaranteed to fail. Use compare() instead.

A shocking number of LLSingleton subclasses had public constructors -- and in
several instances, were being explicitly instantiated independently of the
LLSingleton machinery. This breaks the new LLSingleton dependency-tracking
machinery. It seems only fair that if you say you want an LLSingleton, there
should only be ONE INSTANCE!

Introduce LLSINGLETON() and LLSINGLETON_EMPTY_CTOR() macros. These handle the
friend class LLSingleton<whatevah>;
and explicitly declare a private nullary constructor.

To try to enforce the LLSINGLETON() convention, introduce a new pure virtual
LLSingleton method you_must_use_LLSINGLETON_macro() which is, as you might
suspect, defined by the macro. If you declare an LLSingleton subclass without
using LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() in the class body, you can't
instantiate the subclass for lack of a you_must_use_LLSINGLETON_macro()
implementation -- which will hopefully remind the coder.

Trawl through ALL LLSingleton subclass definitions, sprinkling in
LLSINGLETON() or LLSINGLETON_EMPTY_CTOR() as appropriate. Remove all explicit
constructor declarations, public or private, along with relevant 'friend class
LLSingleton<myself>' declarations. Where destructors are declared, move them
into private section as well. Where the constructor was inline but nontrivial,
move out of class body.

Fix several LLSingleton abuses revealed by making ctors/dtors private:

LLGlobalEconomy was both an LLSingleton and the base class for
LLRegionEconomy, a non-LLSingleton. (Therefore every LLRegionEconomy instance
contained another instance of the LLGlobalEconomy "singleton.") Extract
LLBaseEconomy; LLGlobalEconomy is now a trivial subclass of that.
LLRegionEconomy, as you might suspect, now derives from LLBaseEconomy.

LLToolGrab, an LLSingleton, was also explicitly instantiated by
LLToolCompGun's constructor. Extract LLToolGrabBase, explicitly instantiated,
with trivial subclass LLToolGrab, the LLSingleton instance.

(WARNING: LLToolGrabBase methods have an unnerving tendency to go after
LLToolGrab::getInstance(). I DO NOT KNOW what should be the relationship
between the instance in LLToolCompGun and the LLToolGrab singleton instance.)

LLGridManager declared a variant constructor accepting (const std::string&),
with the comment:
// initialize with an explicity grid file for testing.
As there is no evidence of this being called from anywhere, delete it.

LLChicletBar's constructor accepted an optional (const LLSD&). As the LLSD
parameter wasn't used, and as there is no evidence of it being passed from
anywhere, delete the parameter.

LLViewerWindow::shutdownViews() was checking LLNavigationBar::
instanceExists(), then deleting its getInstance() pointer -- leaving a
dangling LLSingleton instance pointer, a land mine if any subsequent code
should attempt to reference it. Use deleteSingleton() instead.

~LLAppViewer() was calling LLViewerEventRecorder::instance() and then
explicitly calling ~LLViewerEventRecorder() on that instance -- leaving the
LLSingleton instance pointer pointing to an allocated-but-destroyed instance.
Use deleteSingleton() instead.

LLError machinery depends on two different LLSingletons. Its is_available()
function is primarily for LLSingleton itself to determine whether it is, or is
not, safe to log. Until both of LLError's LLSingletons have been constructed,
attempting to log LLSingleton operations could produce infinite recursion.

We've had this functionality buried in llerror.cpp for years. Make it
available for callers outside llerror.cpp too.

Part of LLError's logging infrastructure is implemented with an LLSingleton.
Therefore, attempts to log from within LLSingleton machinery could potentially
go south if LLError's LLSingleton is not yet initialized.
Introduce LLError::is_available() in llerrorcontrol.h and llerror.cpp.
Make LLSingletonBase::logwarns() and logerrs() consult LLError::is_available()
before attempting to use LL_WARNS or LL_ERRS, respectively.
Moreover, make all LLSingleton internal logging use logwarns() and logerrs()
instead of directly engaging LL_ERRS or LL_WARNS.

MAINT-4653 WIP, DRTVWR-397 WIP - log output to file now includes tags. Request max 5 attachments per idle loop to reduce sim-side failures seen when requesting large numbers.

restore the ll[io]fstream because we need them as wrappers on Windows for wide char paths; on other platforms they are now just typedefs to the std classes

MAINT-4009: Final pass refactoring to eliminate memory allocation related to error reporting that is not properly cleaned up.

MAINT-4009: First pass refactoring to eliminate memory related to error reporting that is not properly cleaned up.

MAINT-4009: Converting the Globals class within llerror to be derived from LLSingleton so that it may be cleaned up properly on app exit.

 - memory leaks fixing;

- Added clear() after DeletePointer() call to hopfully fix this...

 - memory leaks fixing;

manipulation of callsite strings in llerror

SH-4346 FIX: Interesting: some integer Statistics are displayed as floating point after crossing region boundary
made llerrs/infos/etc properly variadic wrt tags
LL_INFOS("A", "B", "C") works, for example
fixed unit tests
remove llsimplestat

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

consolidated most indra-specific constants in llcommon under indra_constants.h
fixed issues with operations on mixed unit types (implicit and explicit)
made LL_INFOS() style macros variadic in order to subsume other logging methods
such as ll_infos
added optional tag output to error recorders

there are no samples during the time period.
added hasValue to SampleAccumulator so we don't print a value when we don't have
a single sample yet
added some disabled log output for scene load timing