Improved performance a lot.
	- A big performance penalty was caused by how lua handles the creation of functions in metatables.
	- Improved performance by not calling the relatively slow type() function in some commonly executed pieces of code.
Fixed being able to change non static members of the global class instance. (which would reflect back on any new instances)
Fix being unable to concat classes in strings.
Fixed instance_of not working.
Added global isclass and isinterface functions.