[Ironruby-core] Mono fixes committed

[Seo Sanghyeon]

Thanks to Jim Deville, I got a SVN commit permission yesterday. I have
committed Mono fixes, so current SVN trunk should build with Mono SVN
trunk (sorry, you can't build with Mono 1.9.x.)

r129: Do not use *.csproj which contains Windows paths
r130: Change the visibility of NodeFlags enum to workaround a Mono bug
r131: Add missing references

-- 
Seo Sanghyeon