Attempt to fix flaky AMO tests by not relying on ExtraAppTestCase anymore

ExtraAppTestCase causes problems depending on import order, because
any models with FKs that is imported get cached into its related
model's _meta._related_objects_cache.
set tabzilla to default z-index (bug 927168)
a minor, but key, fix
fixed search merorizing version (bug 729414)
Merge pull request #1267 from diox/fix-flaky-tests

Attempt to fix flaky AMO tests by not relying on ExtraAppTestCase anymore
Merge pull request #1264 from vinyll/version_sidebar-729414

fixed search merorizing version (bug 729414)
Commit from Mozilla Verbatim by user kelemeng.: 2169 of 5452 strings translated (3 fuzzy).
Commit from Mozilla Verbatim by user toniher@softcatala.org.: 2080 of 5452 strings translated (7 fuzzy).
Commit from Mozilla Verbatim by user michael.koehler1@gmx.de.: 5452 of 5452 strings translated (0 fuzzy).
add in a shared column (bug 925830)
move score dashboard to rev home, points msg (bug 875118)
Merge pull request #1286 from ngokevin/movepoints

move score dashboard to rev home, points msg (bug 875118)
Commit from Mozilla Verbatim by user michael.koehler1@gmx.de.: 5452 of 5452 strings translated (0 fuzzy).
Merge pull request #1290 from andymckay/925830

add in a shared column (bug 925830)
fix rev test by catching unicode err
Commit from Mozilla Verbatim by user besnik@programeshqip.org.: 1580 of 5452 strings translated (0 fuzzy).
Merge branch 'master' of ssh://github.com/mozilla/zamboni
Add MONOLITH_INDEX to dev and stage marketplace settings.
Removed skipTest since bug has been fixed (bug 883477)
bump newrelic