Fix some string to float casting nastiness. The "train script" now

works. Also makes llGetFreeMemory return the constant 16384.
LLGetFreeMemory is useless in SL, as it never goes up, only down.
So, the only thing it is used for, in practice, is to detect an imminent
stack/heap collision, a danger we don't have.

OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs

@@ -4597,8 +4597,9 @@ namespace OpenSim.Region.ScriptEngine.Shared.Api
         public LSL_Types.LSLInteger llGetFreeMemory()
         {
             m_host.AddScriptLPS(1);
-            NotImplemented("llGetFreeMemory");
-            return 0;
+//            NotImplemented("llGetFreeMemory");
+            // Make scripts desined for LSO happy
+            return 16384;
         }
 
         public LSL_Types.LSLString llGetRegionName()