Add modules page that documents the module interaction.
Includes a graph made by graphviz with fancy URL's to the rest of the documentation.
To test:
- check out this branch
- Make sure you have graphviz installed
- cd docs
- make html
- In a browser, go to file:///docs/build/html/modules.html
Also fix OCSPAdder docstrings and add that to the index.
Closes #6 (closed)