Add 'full table of contents' page to docs
Docs: remove depth limit from full toc
Fix the docs PDF build
[#1305] Fixes popover error by checking for it's existance in the plugins
Reorganize Solr setup docs

Sphinx doesn't support "inner pages" like the Solr setup page was trying
to be, it breaks Sphinx's navigation.

Move the single-core Solr setup docs into the source install docs,
inline.

And an appendices chapter to the docs, and move the multi-core Solr docs
into it.

Also add new docs for setting up a second Solr core when using
multi-core.

Also tidy up some Sphinx heading styles.
Merge branch '1305-undefined-popover'
Merge branch 'master' into docs-full-table-of-contents

Conflicts:
	doc/index.rst
Merge branch 'docs-full-table-of-contents'
Merge branch 'master' into solr-docs-reorg

Added appendices/index.rst to the contents.rst main TOC

Conflicts:
	doc/index.rst
Merge branch 'solr-docs-reorg'