Allow plugins to have a process callback so they can modify the plugin directly to provide smarter defaults, plus add some more formal documentation in the advanced help.

- a tool for AJAX, which is the next generation tool based on what Views uses.
- a tool for modals -- completely ripping the modal out of Panels.
- moving plugins for 'arguments', 'relationships' and 'contexts' into CTools.

Chaos Tools API initial, early checkin. This module provides 4 API tools, plus an early version of the delegator module. See http://views2.logrus.com/overrides for a discussion of delegator.module.