Fix some problems found during documentation build:
* Remove reference to obsolete files
* Fix warning about too short title underlining
* Include api reference in index page
* Include man page in index page
* We have no _static files, so don't set the config option for it
* Fix reference for tests.share
Change-Id: I798d1ab65184689d75c559de9bffdf5969b9f013
After manila's fork from cinder, its docs were not
updated well.
This info is used by doc-builder, see doc/README.rst
Partially implements: blueprint manila-documentation
Change-Id: Ic97584db291b60505d5d310a517c2866fc6fcf5f