[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

indra/newview/app_settings/settings.xml

@@ -15398,6 +15398,28 @@ This should be as low as possible, but too low may break functionality</string>
       <key>Value</key>
       <integer>0</integer>
     </map>
+    <key>SpeakerParticipantDefaultOrder</key>
+    <map>
+      <key>Comment</key>
+      <string>Order for displaying speakers in voice controls.  0 = alphabetical. 1 = recent.</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>U32</string>
+      <key>Value</key>
+      <integer>1</integer>
+    </map>
+    <key>SpeakerParticipantRemoveDelay</key>
+    <map>
+      <key>Comment</key>
+      <string>Timeout to remove participants who is not in channel before removed from list of active speakers (text/voice chat)</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>F32</string>
+      <key>Value</key>
+      <real>10.0</real>
+    </map>
     <key>UseNewWalkRun</key>
     <map>
       <key>Comment</key>