Shaving4Minutes - decoupling JS and .NET UnitTests

When investigating .NET or JS UnitTest failures we always had to run both kinds. This was especially irritating when targeting .NET unit tests only because JS unit added ~4 minutes to each run. Now we have separate targets for .Net unit tests and JS unit tests and therefore we can run just one kind of unit tests. Note that the RunUnitTests target works as it was before (i.e. runs both JS and .NET unit tests).