Removed auto-generated doc files.
Moved all png images into images folder.
Removed auto-generated modules.rst.
Reference png files in images folder.
Added a pre-hook that calls sphinx-apidoc.
Build docs as part of Travis CI.
Merge remote-tracking branch 'upstream/master' into add-autobuild-docs

Conflicts:
	.travis.yml
Merge pull request #85 from mcflugen/add-autobuild-docs

Clean up the docs folder