Sphinx: treat warnings as errors
Sphinx: Move index.rst and conf.py into src/

Few paths had to be updated. This fixes the following Sphinx warning/error:

theoretical-physics/README.rst:: WARNING: document isn't included in any toctree
Sphinx: use verbose output

This shows progress at Travis.
Move _static/ into /src/

This should have been part of b128e2be10d174aa295d0bd5173acc40ec6a66d3.
Merge pull request #25 from certik/travis2

Travis: treat all warnings as errors