[Voice Update] Apply updates from Viewer-Vivox2

Applies the following commits:
 4c13e7c - Interim version with SLIM removed from voice.
   https://bitbucket.org/obscurestar/viewer-vivox2/commits/4c13e7c7535cbae2767181844a014897c85f254a
 9cad21a - Thanks mercurial.
   https://bitbucket.org/obscurestar/viewer-vivox2/commits/9cad21adc15947f74a1beda31264730361fc6569
   Only the changes that should have been in 4c13e7c (removal of LLVivoxVoiceClient::accountListBlockRulesSendMessage() and LLVivoxVoiceClient::accountListAutoAcceptRulesSendMessage())
 9c94b96 - Removed debugging.
   https://bitbucket.org/obscurestar/viewer-vivox2/commits/9c94b96ed3ac20987f308b5296fba1cc51a875b1
 ec77595 - Turn off logging.
   https://bitbucket.org/obscurestar/viewer-vivox2/commits/ec775958ef8c2923ddc03ed051e322310dc278cd
 857cab1 - Kill all the vivox logs
   https://bitbucket.org/obscurestar/viewer-vivox2/commits/857cab153e835211d0a76e66d627a14de0f4706b
[Voice Update] Further sync llvoiceclient and llvoicevivox with upstream

Mainly tiny motions to ease merging as viewer-vivox2 work continues
Condenses MultiVoice block
Don't explicitly set LIBGL_DRIVERS_PATH by default; breaks autodetection
Fix shader compilation/out-of-spec issues
Merge remote-tracking branch 'upstream/master'

Conflicts:
	indra/llrender/llshadermgr.cpp (resolved)
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'
Merge remote-tracking branch 'upstream/master'

Conflicts:
	indra/newview/app_settings/shaders/class1/deferred/alphaNonIndexedNoColorF.glsl
	indra/newview/app_settings/shaders/class1/deferred/fullbrightShinyF.glsl
	indra/newview/app_settings/shaders/class1/deferred/fxaaF.glsl
	indra/newview/app_settings/shaders/class1/deferred/giF.glsl
	indra/newview/app_settings/shaders/class1/deferred/multiSpotLightF.glsl
	indra/newview/app_settings/shaders/class1/deferred/softenLightF.glsl
	indra/newview/app_settings/shaders/class1/deferred/spotLightF.glsl
	indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl
	indra/newview/app_settings/shaders/class2/deferred/alphaNonIndexedF.glsl
	indra/newview/app_settings/shaders/class2/deferred/alphaNonIndexedNoColorF.glsl
	indra/newview/app_settings/shaders/class2/deferred/multiSpotLightF.glsl
	indra/newview/app_settings/shaders/class2/deferred/spotLightF.glsl
Re-fix shader compilation errors
Add option to disable scroll offset changing modifier
Err closer to LL regarding shadows, however also fixed alpha face shadows to look like all other shadows.
Retain cubemap reflection on shiny faces while in shadowed, but don't bloom the sun reflection.
Avoid needless second pass on non-glow particles.
Added setting 'SHAlwaysSoftenShadows' to soften shadows when ssao isn't enabled. Removed a couple dead settings.
Merge remote-tracking branch 'lightdrake/master'
Merge branch 'master' of git://github.com/Shyotl/SingularityViewer
Merge branch 'master' of https://github.com/DamianZhaoying/SingularityViewer