Add ability to disable look at hints

Author: FelixWolf

indra/newview/app_settings/settings.xml

@@ -16256,5 +16256,16 @@
       <key>Value</key>
       <integer>1</integer>
     </map>
+    <key>EnableLookAtHints</key>
+    <map>
+      <key>Comment</key>
+      <string>Whether or not to send animate the avatar head and send look at hints when moving the cursor or focusing on objects</string>
+      <key>Persist</key>
+      <integer>1</integer>
+      <key>Type</key>
+      <string>Boolean</string>
+      <key>Value</key>
+      <integer>1</integer>
+    </map>
 </map>
 </llsd>

indra/newview/llhudeffectlookat.cpp

@@ -392,6 +392,12 @@ void LLHUDEffectLookAt::setTargetPosGlobal(const LLVector3d &target_pos_global)
 //-----------------------------------------------------------------------------
 bool LLHUDEffectLookAt::setLookAt(ELookAtType target_type, LLViewerObject *object, LLVector3 position)
 {
+    static LLCachedControl<bool> enable_lookat_hints(gSavedSettings, "EnableLookAtHints", true);
+    if (!enable_lookat_hints)
+    {
+        return false;
+    }
+
     if (!mSourceObject)
     {
         return false;