Some updates for 3.8

First commit replaces the deprecated DBus import with the new stuff (been there since 3.4 I guess, but I'm only testing against 3.8).
Oh, in case you wonder: Using a variant for "StopTracking" seems to work with the version found in Debian (hamster-applet 2.91.3+git20120514.b9fec3e1-1) as well as with hamster-time-tracker 1.03.3 (where the signature changed to integer), if I tested that correctly here.

Second commit implements a feature I've been using for months now, but never found the time to actually implement it in a configurable way and send a pull request. So here it is.

Last commit is just there to comfort my eyes. Most likely I didn't catch all missing semicolons, we're lucky spidermonkey is forgiving ;)

I wasn't able to get hotkey-binding to work properly, didn't look to thoroughly though.

Let me know what you think.