Increase socket timeout for selenium tests

I can reproduce bug 1100771 consistently in my development environment.
Increasing the socket timeout in the SeleniumTestCase class fixes
the timeout issue for me.

This uncovers another issue that causes an "Address already in use
error". This happens because the order of tear down is wrong - we
need to quit() the driver before continuing with tear down rather
than after.

Fixes bug 1100771.

Change-Id: I95fbea05c3fc2516ce4e736eea9b0823bb5bbf79
(cherry picked from commit 5e58a7e388bf593861a63409ee3ccc20b868a9b5)
Mark additional strings as translatable

Some variables and templates variables that should be translatable
weren't marked as such.

Fixes bug #1180316

Note the change in horizon/templates/horizon/common/_quota_summary.html
is not backported in this commit to keep the existing translations work.

Change-Id: I90baf19c4bea09c126f8ed225777037194f5331f
(cherry picked from commit acfb83d5d5e45506cb2198869bc9e345f87ff6ea)
Merge "Increase socket timeout for selenium tests" into stable/grizzly
Merge "Mark additional strings as translatable" into stable/grizzly