Minimize CsProjFile changes

So we don't have to reload all projects each time we update or install
packages
fix multiple change to csprojfile with some pkg

When using a package that include another dll in his lib folder. And the
other dll exists as a package, then csprojfile are changed multiple
times du to addassemblies save. In that case we have a reload all window
on vs.

Package creating conflicts :
- TweetSharp-Unofficial (embed hammock and newtonsoftjson)
Merge branch 'FxiDuplicateAssemblyName' into YsVersion
Merge branch 'UpdateToNewCsProjFileAndMinimizeChanges' into YsVersion