Bug 1042646 - Deselect job when closing job panel

This work fixes Bugzilla bug [1042646](https://bugzilla.mozilla.org/show_bug.cgi?id=1042646).

This change clears the job selection styles, and re-initializes the internal job "position" for future keyboard job failure navigation, upon a *manual close* of the job panel via the 'x' close icon. Basically it was a case of re-locating those events into the main closeJob function.

So the above behavior is now consistent with all close workflows:

* manual close via the icon
* esc (keyboard) event to close the panel
* clicking "away" from the job on the main page

Here's the appearance pre-close:

![closejobpanelfix_panelopen](https://cloud.githubusercontent.com/assets/3660661/4920561/37dca8b8-6503-11e4-9fbc-40b9b125954b.jpg)

And after close:

![closejobpanelfix_closepanel](https://cloud.githubusercontent.com/assets/3660661/4920565/3d05b910-6503-11e4-88d1-a98b3dc082e8.jpg)

I was only able to test on Firefox with the job panel still not working on Chrome due to [1072346](https://bugzilla.mozilla.org/show_bug.cgi?id=1072346), but everything appears to be working correctly in my testing.

Tested on Windows:
FF Release **33.0.2**

Adding @camd for review and @edmorley for visibility.