Add this library as a Git submodule. We'll be using it to set a
configurable shortcut and pull it when needed from `NSUserDefaults`.

Xcode (4.5.2) was crashing whenever I tried to open the MainMenu.xib
file. A Stack Overflow post turned up that recommended removing this key
in order to get it working again:

http://stackoverflow.com/questions/27167679/xcode-6-1-crashes-whenever-i-use-interface-builder/27932154#27932154

Sure, works for me.

This new target will be used as our non-background user-facing
configuration application. It's purpose will be to define a custom
shortcut to trigger the mouse move & click action.

Since this is a backround app
(3db243f3c84f7ab36747f4badfd4f57a26563821), we don't have a UI and have
no need for any nib files.

We'll make an additional target as a separate application that does
have a UI and will allow customisation of the global hotkey.

Modify the coordinates such that instead of clicking the center of the
screen, we click the OK button on the low battery warning dialog.

Rename the method according to its new intent.

TODO: This probably doesn't work on other displays that have different
resolutions. We need to check that and figure out a cross-display
solution.

Make this a background-only app. We don't have any UI for the daemon
part of the app. It should just sit quietly until it's called by a
global hotkey to click in the right part of the screen.

Change the last space to a dot to make it more obvious that it's
supposed to mean 'daemon'.

This method isn't reused anywhere so it can go back into the
`moveToCenter` method.

Originally created before `_cursor_position`. See
1832514ab872dec621d5f403eb5328167b3da033.

Method that clicks the mouse.

* Add `_cursor_position` instance var that describes the current cursor
  position after the `moveToPoint` method is called
* `click` will click at the `_cursor_position` point
* I had extracted the centering code to `centerPoint` (which maybe
  should have been called `pointAtCenter`) out of the `moveToCenter`
  method because I briefly used it in `click` as a test before adding
  the `_cursor_position` ivar. This should be reintegrated with
  `moveToCenter`.
* Add a `post_mouse_event` function that abstracts the CG calls needed
  to send a mouse event since we need both click down and up events.

Based on:
http://stackoverflow.com/questions/1483657/performing-a-double-click-using-cgeventcreatemouseevent