Follow-on to fix bug in CORS preflight check.
Revise Rest::approve_origin().
Disallow REST JSONP output with access keys or if blocked by configuration.
Tweak how we store/process some REST config vars.
Add new REST vars to installer (now v4), add admin screen to modify them.
Note: since REST isn't enabled by default, there are no changes to install.sql.
Revise REST relationships to pass on params (useful for "num" parameter).
Merge pull request #410 from shadlaws/fixes_20130615_2

Fixes 20130615 2