Merge pull request #222 from greezybacon/hotfix/api

Fix api user data validation failure

Reviewed-By: Peter Rotich <peter@osticket.com>
forms: Hotfix to correct creating lists
Pluggable authentication

This includes the initial concept of pluggable authentication along with the
initial concept for a plugin management system.
Complete initial sketch of plugin (un)install
Make room for single sign on backends

Like HTTP authentication
plugins: Add upgrade script

And add fixup rebase conflicts, and add nice page for unconfigurable plugins