Remove bipy prefix from doc filenames

Fixes #131.
Support for documenting private/special methods

Adding numpydoc source so that we can extend/customize as necessary (see licenses/numpydoc.txt for license).

Added an extension to the numpydoc standard that allows a developer to tag a method to be included in the built documentation, when it would have otherwise been ignored. This is necessary in order to have special methods (e.g.  __getitem__, __str__, etc.) included in the built docs.
remove numpydoc dep from setup.py and Travis conf
Add readthedocs requirements file
hopefully fix numpydoc link
try mock imports
trying more shit
trying it without install_requires
Merge pull request #134 from jrrideout/issue-129

DOC: remove 'bipy.' prefix and add support for documenting special/private methods
Merge branch 'master' of github.com:biocore/bipy
Merge branch 'master' into issue-120
Add description of shownumpydoc