added sphinx documentation generation
Only rebuilding sphinx when sources change.
Added sphinx cleanup.
Shortened sphinx target to `make sphinx`.
using makefile shortcut for env bin directory
Added the sphinx index to the open target.
sphinxified Item module as example
Replaced @param with :param

for sphinx
Merge remote-tracking branch 'origin/master' into sphinx
removed sphinx output files I forgot I had added.
Converted @return to :return
Replaced @raise DoorstopError: with :raises: :class: `DoorstopError`

for sphinx
The one @raise that had a colon after it
Added class links for doorstop exception classes
Fixed issues with spacing sphinx flagged as warnings
Added links for auto_load and auto_save
Added exclude pattern
took out trailing spaces for pep8

sublime is supposed to take them out when I save, but it doesn't always
work.
Merge 'master' into sphinx.
Merge branch 'master' into sphinx