Updated the Ast, Parser, Scanner, and Sast to support functions
Merge branch 'master' of https://github.com/daperlmu/PLATO

Conflicts:
	Parser.mly
Modified compiler to provide support for functions; basic functionality. The functions are not validated for return type match, satisfaction, etc...Added new tests that reflect the functionality of the functions feature currently supported in the compiler. NOTE: the added feature does *NOT* cause any regressions!
Merge branch 'master' of https://github.com/daperlmu/PLATO

Conflicts:
	Parser.mly