Allow calling LLNotificationsUtil::add from any thread.

This makes LLStringUtil thread-safe by removing a rather unnecessary
LLFastTimer from LLStringUtil::format.

Same thing for LLTrans::getString and LLTrans::findString, where
even a comment stated that the author wasn't interested in measuring
cpu time at all. In this case I added some code back to make sure
that we're not calling LLTrans::getString() in an inner loop, which
was the reason that the LLFastTimer was added.

Made one string static to avoid 45000 look ups during login, which
kinda triggered the above test.

Finally, LLNotificationsUtil::add is made thread-safe by making
LLNotificationChannelBase::mItems thread-safe and defering a call
to LLNotifications::updateItem to the main thread when called
from another thread (using a little statemachine).
Merge remote-tracking branch 'singu/master'
Initialize LLListener_OpenAL::mRolloffFactor just to be safe.
Font update. Minor refactor, and removed some pointless code that was leaking.
Underwater shadows.
Removed fasttimer that was hurting perf a tiny bit.
Fix for 'with active responder' llerrs crash.

This fixes at least one case (crash report 8407), which comes
down to not cleanly informing a responder of failure when the
request url is empty (or so badly formed that it isn't a valid
url). As a result, the statemachine would abort() without
informing the responder - which is bad, sort of.

The previous cases where the responder needed to be informed
of a failure, namely "statemachine timed_out()" and "bad_socket()"
when a socket suddenly becomes bad for unknown reason, have been
replaced with the more general 'aborted()' function, which must
be called before the statemachine calls abort(). Clearly this
has been done for all cases of abort() now, so that if the
llerrs fires again in the future then that would have to be
after the statemachine calls finish(), which is still as "impossible"
as it was - hence the llerrs is still there to make sure.

The reason that this seldom happened on SL, and more often on
opensim, even more often on home-brew test grids, seems plausible:
malformed urls happen more in those cases.

I also took the opportunity to improve the robustness of cases
where the curl error code is checked: it makes no sense to check
what curl gives as error code when an internal error occurred.
Use viewer channel as the basis for installer file names
Mac build changes to create specific channel installers
Merge branch 'master' of git://github.com/AlericInglewood/SingularityViewer
Merge branch 'master' of git://github.com/Shyotl/SingularityViewer