Bug fixes:
----------

* Find git more intelligently, because build_prefix isn't always on PATH  #2196
* Fix up assorted RPM skeleton issues  #2196
* Fix and test "numpy x.x" recipes  #2198
* Fix and test --skip-existing.  Ensure that it also works with --croot.  #2200
* Fix and test "python x.x" recipes  #2201
* Fix inappropriate insertion of variant versions that led to conflicts (for example, numpy)  #2202