Bug 1115194 - Update un-starred term to unclassified in the Help

This tweak fixes Bugzilla bug [1115194](https://bugzilla.mozilla.org/show_bug.cgi?id=1115194).

Per the bug, this change makes the terminology across all the Help shortcut keys consistent regarding classification, and retiring the term 'unstarred'.

Here's the change:

![unstarredtounclassified](https://cloud.githubusercontent.com/assets/3660661/5545872/2af6a9f6-8aff-11e4-93bf-75cb2cf7433b.jpg)

Tested on Windows:
FF Release **34.0**
Chrome Latest Release **39.0.2171.95 m**

Adding @camd for review.
There is no `annotation` class in treeherder.css, but just to keep things consistent here.