VS2010 and VS2012 git management enhancements

Git ignore compiled, utility and user files for VS 2010 and VS 2012.
Git ignore changes made to OwlPatches submodule.
README update to reflect the current sources architecture.

close pingdynasty/OwlSim#11
VS2010 PatchRegistry solution folder

Source/Patches VS filter content removed from OwlSim VS project.
All OwlPatches files added in PatchRegistry VS solution folder. They are
now visible and editable inside VS without interfering with VS
compilation process.
OwlSim VS project is cleaner and contains only VST classes.