Merge pull request #4 from rmcgibbo/master

updates
Add a note on building docs for py3
Use external numpydoc
Use IPython's version of these sphinxexts

Included versions were not kept up to date and
are not py3 compatible.
Fix ReST syntax for headings
Use py3 compatible str.replace
Merge pull request #570 from mpharrigan/fixdocs2

Building docs on Python 3
Remove vestigial numpy_ext
Remove gen_rst as well
Fix import
Cleanup imports
Fix imports
Reduce number of warnings
Fix javascript for discussion forums linl
Organize imports
Cite stack overflow
Install numpydoc for building docs on Travis
Merge pull request #571 from mpharrigan/fixdocs3

Remove more vestigial doc-building stuff
Fix link on side
Update link to pull from simtk/mdtraj