Core compiler + dotnet backend = working

Library = not compiling yet

The evaluator for the macro system is giving me gyp. Need to gut it
and replace with a macro-expander/parser that does a decent job. Phase
separation issues, hello my old friends...

Note that the TailClosure and TailContinuation classes are currently
not properly tail recursive (for debugging purposes)! To make them
tail recursive, change the compilation technique for Newmoon.dll to
include Lowlevel.il, by modifying the Makefile, and remove the
definitions in the C# code for classes that are now to be provided by
Lowlevel.il.