Stop testing on PHP 5.2

This is the beginning of our PHP 5.2 support deprecation.
See also #1830
https://github.com/ginatrapani/ThinkUp/issues/1830
[DB MIGRATION REQ'D] Keep users logged in via long-term cookie

Adds tu_cookies table.
CookieDAO and MySQL Implementation.
Test for DAO.
Check for cookie when not isLoggedIn() in Session.
Kill cookie on logout.
Integration tests for login, and new one for logout.
Updates installer and DAOFactory tests.

Closes #388, closes #1832
Facebook plugin: Swap in short-term token for long-lived token
Test fixes
Send Facebook reauth email to owner, not admin
Facebook plugin: Gracefully handle app-level API rate limiting
Facebook plugin: Gracefully handle "unexpected error please try again" from API