Update to build on Xcode 6.0: clang detecting unsigned int (size_t) comparison with <0 [-Wtautological-compare]

Copy3rdPartyLibs needed to copy the now-corrected fmodexL libraries
and it had a bad library reference on Linux for release.  In
llaudio land, the audio engine interfaces, even the fmodex
specializations, seem to want to be external-structure free
so use a forward declaration and pointer to FMOD_DSP_DESCRIPTION
and deal with it in the ctor/dtor.

MAINT-3804 FIXED Crash in LLAudioEngine::getAudioData when playing gestures with audio device disabled.

- Removed logging for MAINT-3555
- Added NULL guard to fix MAINT-3703 (hopefully)

MAINT-3016 FIX Viewer freeze... by reverting fix for MAINT-2849 (certain streams do not play) - freeze more important than no play

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

Quieten down writing to fmod.log - only write errors - speculate this is related to audio stutter/frame stalls