Reshuffle of services and add trigger for ⌘⎋. Fixes #409

This commit is actually quite simple when it comes down to it. I've made the existing 'Select Current Selection in Command Window' trigger be enabled by default and use the ⌘⎋ shortcut.
I've also removed the 'Send to Quicksilver' service, meaning we now only have one.

Notes:

* Some users may have to re-configure the trigger if they've been using the 'Send to Quicksilver' service (now that it's deleted). But services rarely get flushed/reconfigures so there may well be no need.
* I decided not to merge the Finder and Global Selection code. I think we all understand a bit better now how the two bits of code differ, and when to use one or the other. We also know the limitation of getting stuff from the Finder, so I don't see it work us merging the two.
* The service and the trigger have the same keyboard shortcut, this seems to work fine - we just need to advertise that *only* keyboard shortcut the trigger be changed
* [This](http://stackoverflow.com/questions/2845070/register-nsservice-with-command-alt-nskeyequivalent) is quite a useful read to figure out a bit more about debugging services
* For debugging purposes, using a Guest account helps, but I could only run release builds on the guest account
* To reset your Services, make sure you delete **all** copies of QS (including those in the trash) and run `/System/Library/CoreServices/pbs -flush`. Check the 'Keyboard Shortcuts' sys prefs following this to see the state of services
* We *could* setup the service to use an even more obscure shortcut (like ⌘⌥⌃⎋), so it won't ever realistically conflict with anything else, but I don't see the point