reworked Transifex processes into MSBuild targets
added UpdateVersion.targets to write git hash to various files containing version information
reworked MP2 build script into MSBuild project
replaced BuildReport submodule by NuGet package
updated NuGet.targets to latest default NuGet.targets (but kept modifications)
enabled package restore within NuGet.targets
this also fixed manual translation download
added nuget specifications for MediaPortal 2 core projects