GitLab

Swigged python docstrings now include documented return values and type
information or their arguments. They are generated in numpydoc format.
Furthermore, all of the Python app layer docstrings have been changed
to numpydoc format. The filterPythonFiles.py script which helps to
generate the Doxygen Python API docs has been updated to reflect these
changes.

Add relevant tests (that used to fail). This also fixes a subtle bug where
switching functions were not applied when NBFIXes were specified.

Now that I have my head on straight, that is.

Hard-code CC and CXX to clang for Macs, since gcc/g++ will *not* work with
Anaconda, despite the fact that distutils will try to use them.  System Python,
homebrew, and MacPorts on Macs will always use clang, so this hack should always
work and fix issues with users that have GCC installed from MacPorts or homebrew
*and* Anaconda.