Add a custom hover control for bar charts.

I'm going to try and get this accepted up stream at some point.
[Bug 852042] Questions answered bar does not turn green at 100%.
[bug 849841] Track the outbound download button clicks.
[bug 846770] Up the document_keywords boost to 8.0
[Bug 852181] Make Contributors cron handle no data
[bug 712833] Noindex the questions listing page.
[bug 852573] Add Firefox 21, hide Firefox 18.
[Bug 785850] Limit votes on answers and questions

Limit votes on answers and questions to 10 votes per day of either type.
Votes after the limit of 10 will be silently ignored. The limit is based
on IP addresses for unauthenticated users, or user id for authenticated
users. Authenticatd users are not limited by IP at all.

User IP address is based on X_CLUSTER_CLIENT_IP, if available, or
REMOTE_ADDR if not. X_CLUSTER_CLIENT_IP has shown to be harder to spoof
than X_FORWARDED_FOR.
[bug 845282] Fix mobile focus and refine wrapping
[bug 845292] Product picker on mobile search results
[bug 850703] Make the question/answer parsing locale aware.

So that localized kb links render correctly.
[bug 818027] Mobile get involved page
Fix & -> &amp;
Point mobile users to new get involved pages.
Add empty directory for compressed assets.
[youtube embed] Disable related videos and enable modest branding.
[bug 853904] Fix NoCacheHttpsMiddleware to use request.is_secure()
[bug 842882] Fix wiki.js issue during minification
[Bug 846281] Search Form Refinements

See: https://bugzilla.mozilla.org/show_bug.cgi?id=846281
Some tweaks for search form on search page.