Merge pull request #71 from rjleveque/for_5.2.2

For 5.2.2
Merge PyClaw developer docs with Clawpack developer docs.

Other miscellaneous changes.
Cleanup of some TOCs.
Simplify top-level table of contents.

Also, link directly to citing information from index.html.
Update Clawpack5x.md
Add link to notebook on limiters.
Merge pull request #73 from ketch/add_notebook

Add link to notebook on limiters.
Link directly to full TOC, with condensed one at top.
Merge pull request #72 from ketch/update_docs

Update docs
Merge branch 'master' into for_5.2.2
Final changes from 5.2.2 release combined with improvements by @ketch

* master:
  Link directly to full TOC, with condensed one at top.
  Add link to notebook on limiters.
  Update Clawpack5x.md
  Simplify top-level table of contents.
  Cleanup of some TOCs.
  Merge PyClaw developer docs with Clawpack developer docs.