Fixed the default for the web server port in rb-site.

The default was an integer, which broke generation of some files. It's
now a string, like all other parameters.
Move the Review Board release notes directory up a level.

This was done previously on master, but it looks like the moved file
info wasn't tracked by git. That made updating release notes on 1.7 and
merging painful.

This attempts to fix the situation by redoing the merge on 1.7.x. Master
will then be fixed appropriately.