added support for action links

Hey, I added in support for action links (again!).
I didn't make a conf.launch_handler like you did for url, movie, and audio because all the information in the action launch was self-contained. Although, if you'd prefer it, I can still make things go through conf.launch_handler.
You essentially get the action to launch by ctrl+a or by assigning another key to 'action 2'.