switch to manual nuget package spec

Packages are not build from the solution file anymore.
Rather the package/ is used to build a package for different frameworks.
The powershell script package.ps1 packages a Release build for net45, net40 and wp71
remove unnecessary file references
make debug output available in DEBUG mode only
fix zero-length move text bug (IndexOutOfRange)
Merge branch 'master' of github.com:iigorr/pgn.net

Conflicts:
	src/pgn.NET/pgn.NET.csproj