- farm out everthing to do with rtd out to the sqlalchemy.org site

Conflicts:
	doc/build/builder/mako.py
css updates to better work with RTD badge
- the pronoun removal commit.   there was only one instance of a
standalone gendered pronoun with a gender-neutral subject, but also
have replaced all occurences of "his/her", "his or her", etc.  The docs have always
strived to account for both genders in any non-specific singular pronoun,
however recent controversy in the community suggests
that a zero-gendered-pronoun policy is probably best going forward.

Conflicts:
	doc/build/changelog/migration_08.rst
	doc/build/orm/session.rst
	examples/nested_sets/nested_sets.py

Conflicts:
	doc/build/changelog/changelog_02.rst
	doc/build/orm/session.rst
	doc/build/orm/tutorial.rst
	examples/beaker_caching/advanced.py