[nem-en] building with msbuild

[NoiseEHC]

Committed the stuff, please test it... :)

Currently, it gives two warnings per keyfile setting, have no idea why.

Also compile with "msbuild.exe Nemerle.sln" since with .nproj files it 
will compile Nemerle.dll twice
so it will have two versions again. Another problem is that it always 
compiles the whole stuff as if it
would not obey dependencies (do not know whether it is a bug or feature 
in msbuild...)