Remove more unused things from CryCommon and CrySystem. (#709)

Lots of unrelated removals, I basically tried to remove everything exposed via gEnv that isn't used anymore, and following the threads found a few other things to remove also.

Code/CryEngine/CrySystem/XML/xml.cpp

@@ -1809,8 +1809,6 @@ XmlNodeRef XmlParserImp::ParseFile(const char* filename, XmlString& errorString,
         ParseEnd();
     }
 
-    SYNCHRONOUS_LOADING_TICK();
-
     delete [] pFileContents;
 
     return root;