Changed MemeScript's function/method declaration syntax.

Here is the new syntax:

module foo() {

  main: fun() {
   ...
  }

  class Foo {
    init new:          fun() { ... }
    instance_method a: fun() { ... }
    class_method b:    fun() { ... }
  }
}
Revamped the entire CompiledFunction scheme.

-No more FunctionLoader / simplified loading when compiling individual
functions.
-Split the original CompiledFunction.new to create toplevel or closure
 functions.
-Split the original CompiledFunction.asContext to use either a var
 dictionary or a stack frame separately (apparently fixed some bugs on
 env handling along the way).

and other smaller things.
Fixing instantiate_module call arity