Automark: first release

Simple plugin that automatically highlights current word (no hotkeys or so on):

![Automark](http://i.imgur.com/q6YyuN4.png)

Now I should touch 16 files, right? (remembered that magic number)
> Note however that you could replace your destroy notification by simply setting source_id=0 inside the timeout callback.

Not sure that this will not cause a race condition because of some internal GLib stuff with removing source while I remove source by hands at the same time.