Added Convert.to_module() method which converts a string into a module caller.

Example:
	"SomeModule".to_module.new;   # to module conversion, without require
	require("SomeModule").new;    # same thing, but with require

Improved the Sys object; Now, Sys.eval() returns unknown references as they are, without converting them to strings;
Added Sys.bless() method to bless an object in other class;