Removed runtime errors that would prevent adding blowing boundary conditions if the problem is 3D. Class Problem now accepts 3D blowing boundary conditions and the core of the API allows it as well.

Merged branch adri into paul

Modified dartflo CMakeLists to set the rpath correctly.

Improve switching function. Lower numerical viscosity. Lower threshold Mach for high speed clamp. Disable Netgen opti. Adapt tests.