Link to the 'dev' manual and not the 1.7.x manual.

We had the links wrong up until now for the Documentation link, so fix
that up in order to link to the in-development manual. This will go out
in the RC.
Remove "Review groups cannot be created or modified through the API." text.

When we added the ability to create or modify review groups through the API, we
neglected to remove the text that said you couldn't do it. This was highly
embarassing and probably contributed to many of the questions we've received
over the past year or so. Trivial change.
Merge branch 'release-1.7.x'