simple class functions

does not include virtual calls
class functions currently do not have a 'this' member
currently treated as simple scoped functions, accesible through 'dot' expressions
added separate functions for basic operators
check error level before attempting to link
cleaner call on function type

WIP class 'this' on dot expressions
reorganized tests
added nomangle keyword - prevents name mangling

extern symbols are now weak
non-extern symbols are not; link time undefined symbols should occur
correctly index class members from supertype
added uniform function call syntax
added implicit 'this' variable

class members are indexable through 'this'
functions are callable through class instance
added implicit 'this' member lookup
added 'implicit_this' extension

added unary dot operator as a short hand for 'this.'
successfully validate types before codegen
updated readme with class info

moved tuple info from future to feature
fixed uninitialized memory issue
load virtual(indirect) functions (WIP) TODO: correct vtable

correctly loading functions from the vtable with some issues
vtable is currently not properly set
vtable lookup index is currently always zero, regardless of method
virtual functions are *not* usible at this time
test dynamic function call in class

currently all dynamic calls call the same test function
TODO: set up vtable to contain class methods
can now have function pointer arrays
full virtual function calls on classes

TODO: function overriding
TODO: non-virtual function calls on classes of known type
reorganized README, moved design justification to DESIGN.md
virtual function calls

correctly set up vtable, including overriding methods
TODO: fix non-virtual function calling (important for union/struct)
fixed non-virtual function calling with structs
merge classes branch; add classes