Removes the f*µù$£ "Bcl portability pack" since retargeting framework/reinstalling packages do not work and lead me to a nervous breakdown.

- CallerFilePath/LineNumber/MemberNameAttribute are now defined by CK.Core.dll in net 4.0.
- Removes nuget old way to restore packages. Now using automatic (see http://docs.nuget.org/docs/workflows/migrating-to-automatic-package-restore).