Handle overriding of environment values

[Jegp]

Figure out how definitions, functions and objects should behave when overloaded.
Case 1:
def H() = {} def h = 1
Case 2:
def H() = {} def f() = { def h = 1 }

[Jegp]

Note to self: Funtions should like objects be a type in itself, parameterised over the name and parameters. The overridding would then happen on the case class level, like objects.