[Voice Update] Break out llvoicechannel.* from llimpanel.*
[Voice Update] Remove gVoiceClient occurrences in favor of using LLVoiceClient as a Singleton everywhere.
Fox the Octopus break I caused
[Voice Update] LLVoiceClient

Migrate a bunch of classes out of llvoiceclient.* and into new llvoicevivox.*
Update most of these to match their counterparts
Introduce VoiceFonts support (voice morphing, floater still to come)
Support for a bunch of v3 voice settings.
Move volume settings management from LLMutelist into LLSpeakerVolumeStorage
Support for Avaline mutes (WIP)
Adds voice section to LLAgent
Moved llfloatervoicedevicesettings to llpanelvoicedevicesettings, v3's voice device panel design is more intuitive.
[Voice Update] llfloateractivespeakers.* to llspeakers.*

Condenses the three moderation responders to one.
Adds Speakers settings.
Uses dedicated timer class to track speakers on the list
Adds temporary getSpeakerManager() function to LLFloaterIMPanel to play the role of LLIMModel::getSpeakerManager
[Voice Update] Minor update to llvoicechannel class

Incompatible things left in from upstream are commented out
Just need to wrap things up to a point.
[Voice Update] LLPanelActiveSpeakers to LLParticipantList

Minor updates to code, mostly just a migration with some v3 stuff commented, since we don't have LLAvatarList and must use buttons since scrolllist menus don't actually exist nicely yet.
Added toggleMuteVoice and isVoiceMuted to LLAvatarActions
Added a minor touch to the voice volume slider, it'll now offer changing your own volume while in an active voice session.. nice to not drop out of an import voice session just to fix yourself.

Also, fix a bug with SpeakerMgr's not flagging speakers for removal properly, causing external speakers and speakers managed by LLActiveSpeakerMgr to never actually get removed.
[Voice Update] Fix the current voice chat button

If the current voice chat's floater is undocked, grab it by session id so that it's not labeled blank
When the button is clicked, open the current voice chat floater, not the communications floater, this is the intended action.. how it should have acted in the first place.
Fix WARNING: LLNotificationTemplates::addTemplate: LLNotifications -- attempted to add template 'LandBuyAccessBlocked' twice.
Merge branch 'master' of https://github.com/singularity-viewer/SingularityViewer into VoiceUpdate
class LLOfferInfo update
Missed a spot
Merge remote-tracking branch 'melanie_t/master'
Merge remote-tracking branch 'lirusaito/master'
Merge remote-tracking branch 'aleric/master'
Need to export BackTrace::S_Number to use BACKTRACE.