added MappedDiagnosticsLogicalContext ($mdlc)

added support for the equivalent to log4net.ThreadLogicalContext
Added functionality for handling diagnostic state across multiple threads in asynchronous situations.
Renamed projects (NLog.Contrib and NLog.Contrib.Tests to remain consistent with other projects.)
Adding Bruno's name to the authors and adding to the description of the NLog.Contrib project.
Uncommenting the build script to push all components when run again.
Merge pull request #8 from toddmeinershagen/master

New MappedDiagnosticsLogicalContext