Increased octree limit to 32k. Addresses "4096 bug" in Opensim

Thanks to NickyD for tracking down the cause.

Refereces:

https://jira.secondlife.com/browse/SVC-2941
http://redmine.kokuaviewer.org/issues/465
http://jira.phoenixviewer.com/browse/FIRE-11593

indra/llmath/lloctree.h

@@ -1010,7 +1010,7 @@ public:
 		}
 		
 		LLVector4a MAX_MAG;
-		MAX_MAG.splat(1024.f*1024.f);
+		MAX_MAG.splat(32767.f * 256.f); // Singu note: SVC-2941 FIRE-11593 maximum increased to 32768 sims across from 4096
 
 		const LLVector4a& v = data->getPositionGroup();