This is just a pre-release for you guys to comment and see if I forgot anything and make feature requests and change requests. Some things don't work, like the "is rotating" condition, or the "when not aiming" property. I'm just rushing this out the door because I don't have much time to work on it, but as you can see, the major stuff is done.
I have included an example with the file, which you can also preview, live, at http://dl.dropbox.com/u/39044660/Turret/index.html, courtesy of dropbox
The link for the behavior and example:
Download Turret Behavior
Remember the behavior is not optimized, therefore might run sluggishly for big projects.
Also, this is a behavior, not a plugin, so it should be extracted to the BEHAVIORS folder, under a "turret" folder of the appropriate name.