Fixed issue #10 - System.OverflowException: Arithmetic operation resulte...

...d in an overflow (64-bit systems) by replacing most calls to ToInt32 with ToInt64

Fixed issue #16 - NuGet error "Package restore is disabled by default." when building by updating to NuGet 2.8.1
Including Vestris.ResourceLib.pdb and Vestris.ResourceLib.xml in release zip for documentation and easier debugging support
Updated documentation references in sln