Use a tree structure for the type system

[lyncmi07]

Under the current system it is not possible to nest modifiers to types (i.e. a pointer to a pointer cannot be created). The type system needs to be changed to support this kind of nesting behaviour.

[lyncmi07]

This will require changes to function overload equivalency functions in Com.NoSyn.Environment.FunctionEnvironment Currently it equivocates variadic versions of a variable to constant versions but not to pointers. In the new implementation the variadic type would specify the full type of the variable that can be used whether that be constant of pointer (or pointer to pointer etc)