[PATCH] Construct Makefiles for the Python library with automake.

[Chris Brannon]

I wrote:
> automake provides support for building and installing Python packages.
> As of this commit, we use it, instead of calling setup.py in
> src/python/Makefile.in.

I forgot to check HAVE_PYTHON in my last patch, so the build could not
be conditionalized.
I added that check.  make only builds or installs the contents of
src/python if Python is available.
I'm resending the patch, rebased against the master branch.
Please ignore the previous version.

-- Chris