.NET compatible wrappers for L collection classes

[degory]

To support compiling the compiler itself for both .NET and L targets, without an unmanageable amount of conditional compilation throughout the codebase, we need a way to reference collections that will compile on both targets.

Aiming to achieve this by writing ghul wrappers around the L collection classes that present .NET compatible interfaces (translated slightly via IL renaming to have a more ghulish feel)

#276 depends on this