Removed unused arguments in the definitions of some core objects.
Fixed a bug that caused Cases and Cases2 to return wrong results when used
with SUNDeltaContract.
Added unit tests for FeynCalcInternal.
Added unit tests for FeynCalcExternal.
Fixed wrong contexts in FeynCalcExternal.
Fixed two typos in FeynCalcInternal.
Improved handling of explicit Lorentz and SU(N) indices in
SU(N) and Dirac matrices.
Corrected unit tests for DiracReduce.
Small fixes for the QCD examples.