Make automodsumm work with templates

[fredrik-1]

I didn't get automodsumm to work with templates in the way that I wanted #46.

This is a solution that works for my application but I don't understand the code enough to know if there are any serious drawbacks. The issues where:

• I got an error because the underline filter didn't exist.
  • I just copied some code from sphinx generate.
• The pages with a new autosummary directive for each class wasn't generating new pages.
  • I just copied some code from sphinx generate once again.
  • I also made it possible (I think at least) to use automodsumm in the template when that make sense.

Fix #46