#172773 by numerous contributors: Make the actions interface usable by mere mortals (including rename of actions.module to trigger, but keeping the actions themselfs).

Complete previous history of actions module:
 - #148410 by jvandyk: added rewrite of the actions module!
 - #155986 by Uwe: fixed typos.
 - #155828 by Eaton, pwolanin and jvandyk: let actions live even if actions.module is not turned on