Functional, but still in progress.

fixes #1679924 by Dave Cohen: Infinite reloads, aggressive cache and third-party cookie problems, and other javascript improvements

by Dave Cohen: more changes from D6 branch merged to D7.  Javascript to show/hide connected markup.  Form alters for user register.

fixes: #1166272 by Dave Cohen, John Klehm: support for facebooks oauth 2.  Mostly an upgrade of fixes from 6.x branch.

Expand fieldsets by default when creating new application.

Change the fb_cb url rewrite syntax.  Now use apikey instead of label.  This helps simplify fb_settings.inc.
multiple simplifications (fixes, lets hope) to fb_settings.inc.
fb_session.inc no longer needed (at least for time being).
more sanity checks and output in fb_devel.module

changed 'fb_session_no' to 'fb_session_handoff'
changed order of javascript event handling, hope to avoid bogus session change events.

numerous changes, especially to session management and url rewriting. performance improvements and code simplification.