[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
Merge remote-tracking branch 'singu/master'
Remove ambient occlusion darkening from all deferred shaders except the one that actually calculates occlusion values.. (aka every shader except class2/softenLightF.glsl)
Merge remote-tracking branch 'singu/master'
Fix Issue 1222 by changing the default Field of View for mouselook zoom

Smooth scroll changes the meaning of the numbers, unfortunately.. so for those who haven't figured out how to customize their mouselook zoom, this'll hafta do.
Also clarified the description of the debug.
SV-1222 #close Fixed up, will require a reset of the debug setting "zmm_mlfov", clean install, or just scroll to modify it.
LLUICtrl support for "enabled_control" and "disabled_control" attributes from upstream.
Modernize LLIconCtrl

Adds min_height and min_width attributes
Adds mPriority for controlling priority with which to call LLUI::getUIImage*
Moves specialized setImage()s into setValue
Removes mImageName and mImageID, value is stored in base as LLSD now
LLInitParam/LLUI Params enhancement

Specialized param handling for common linden types
And pre-viewer-interesting modernized llinitparam.* (includes llsdparam.cpp update)
LLUICtrl Params

Also adds support for requests_front boolean attribute to lluictrl from upstream
Fixups to mistakes of the past.
LLIconCtrl Params
Attempt to fix Issue 1264: Vacant lines in Friends list
Turn noisy AudioEngine debug output into Debug Level.
Merge branch 'master' of https://github.com/singularity-viewer/SingularityViewer
Default SinguOffsetScrollKeys to false and expose it in Camera prefs.

Adds "Scrolling with control and/or shift held adjusts camera position" to Input & Camera prefs
[Radar] Feature request: Have Focus Next/Prev wrap around when it reaches the end
Fix Issue 1273: Typing in Group Chat opens IM Window for other participants

Broken logic, my bad.
Feature request: Add EnableNongestureSounds as an opposite to gesture mute
Stop occasional crash during shutdown