VS2012 & VS2010 solutions enhancements

Ok, now it's good for me. Sorry for all the junk commits and issues I created. I needed to familiarize myself with GitHub, VS2012 Express and C++ VS solutions because I use SVN, VS2010 Premium and C# VS solutions at work. I hope you'll forgive my enthusiasm :-).

I used Visual Studio solution folders which are not manageable in Express editions but can be read by them. However, Express users can manage these folders by manually editing the text file OwlSim.sln. I can create a tutorial for them if needed.