- reword the paragraph which talks about web framework integration for sessions:

1. fix the typo in the paragraph, fixes #2998
2. as zope-sqlalchemy only provides transaction integration and not session scoping,
dial back the language here as people are probably using scoped_session with pyramid anyway
3. as I'm going to again start recommending people don't cling to flask-sqlalchemy so hard,
take out the word "strongly" from the recommendation.
4. as flask is the only framework I can think of that actually has an explicit SQLAlchemy
layer that handles setting up scoped_session, take out the word "most", now it's "some web frameworks"
(by which it means "only flask...and flask-sqlalchemy is probably not worth using anyway")