Don't center links in 320 mode. Refs Bug 868199.
Add back secondary line on fx-not-up-to-date. Refs Bug 868199.
Condense things vertically on 320 so the call-to-action is visible on page load on fx phones, android and older iphones.
Merge pull request #7 from gauthierm/nburka-bug-868199-unified-download

Small updates from Holly as mentioned on Bug 868199