Revert "Bug 921721 - hotfix to bust JS Exception in startup a=testonly r=me"

This reverts commit 5cf27888e390526c072d4b44a5af54c8aaf7205a.
Bug 923831 - Intermittent failures in test_kill_all, disabling the test until someone can investigate and/or repair the test
Bug 923831 - Intermittent failures in test_kill_all, fix manifest syntax a=testonly r=me
Bug 932859 - Apply the SI/SL message styles correctly r=julienw