Allow btBulletWorldImporter to convert/export a .bullet file to XML

Add first version of btBulletXmlWorldImporter, still incomplete but it can read some files
Fix false assert in btSequentialImpulseConstraintSolver

Extras/Serialize/BulletFileLoader/btBulletFile.h

@@ -67,7 +67,7 @@ namespace bParse {
 		// experimental
 		virtual int		write(const char* fileName, bool fixupPointers=false);
 
-		virtual	void	parse(bool verboseDumpAllTypes);
+		virtual	void	parse(int verboseMode);
 
 		virtual	void parseData();