Also add corresponding LLEventTimeout::post_every(), post_at(), post_after()
methods.

LLEventLogProxy can be introduced to serve as a logging proxy for an existing
LLEventPump subclass instance. Access through the LLEventLogProxy will be
logged; access directly to the underlying LLEventPump will not.

LLEventLogProxyFor<LLEventPumpSubclass> functions as a drop-in replacement for
the original LLEventPumpSubclass instance. It internally instantiates
LLEventPumpSubclass and serves as a proxy for that instance.

Add unit tests for LLEventMailDrop and LLEventLogProxyFor<LLEventMailDrop>,
both "plain" (events only) and via lleventcoro.h synchronization.

LLStoreListener is an adapter initialized with a reference to an LLEventPump
on which to listen, a reference to a variable into which to store received
data, and an optional llsd::drill() path to extract desired data from each
event received on the subject LLEventPump.

In effect, LLStoreListener is like a miniature LLEventAPI whose only operation
is to store to its destination variable.

The new behavior is that it will flush when either the pending batch has grown
to the specified size, or the time interval has expired.

For some reason there wasn't an entry in indra/llcommon/CMakeLists.txt to run
the tests in indra/llcommon/tests/lleventfilter_test.cpp. It seems likely that
at some point it existed, since all previous tests built and ran successfully.
In any case, (re-)add lleventfilter_test.cpp to the set of llcommon tests.
Also alphabetize them to make it easier to find a particular test invocation.

Also add new tests for LLEventThrottle.

To support this, refactor the concrete LLEventThrottle class into
LLEventThrottleBase containing all the tricky logic, with pure virtual
methods for access to LLTimer and LLEventTimeout, and an LLEventThrottle
subclass containing the LLTimer and LLEventTimeout instances and corresponding
implementations of the new pure virtual methods.

That permits us to introduce TestEventThrottle, an alternate subclass with
dummy implementations of the methods related to LLTimer and LLEventTimeout. In
particular, we can explicitly advance simulated realtime to simulate
particular LLTimer and LLEventTimeout behaviors.

Finally, introduce Concat, a test LLEventPump listener class whose function is
to concatenate received string event data into a composite string so we can
readily test for particular sequences of events.

plus LLEventBatch::getSize(), setSize()
plus LLEventThrottle::getPostCount() and getDelay().

The interesting thing about LLEventThrottle::setInterval() and
LLEventBatch::setSize() is that either might cause an immediate flush().

These classes are as yet untested: they are straw people for API review, based
on email conversations with Caladbolg and Rider.

MAINT-6336: Put the timeout upstream of the suspending pump and fire the timeout it. Also some cleanup on LLSD construction in vivox.

MAINT-6336: Centralize waiting on event pump with a timeout. Shorten the lifespan of a timeout event pump lifespan to be no longer than necessary. Change all references to the LLEventTimer to instead uses the centralized version.

MAINT-6336: Crasher showing up in voice was a Bound Listener that should have been a Temp Bound listener.

Ok, finally got this to a point where it doesn't break the build and I can check
in. llcommon can be built as a shared library (disabled but can be enabled with
cmake cache var LLCOMMON_LINK_SHARED.

reviewed by Mani on tuesday (I still need to get his suggested changes
re-reviewed)

svn merge -r113003:119136 svn+ssh://svn.lindenlab.com/svn/linden/branches/login-api/login-api-2 svn+ssh://svn.lindenlab.com/svn/linden/branches/login-api/login-api-3