[Fix Bug 950801] Implemented Tabzilla Translation Bar

Squashed commits:
[899580b] added canonical-url from bedrock
[60dfab6] [Fix Bug 950801] Implemented Tabzilla Translation Bar
[063f578] Cleaned up import lines to follow code style guide
[937cca7] added newlines at the ends of new files
[5688ab3] checked against flake8
Merge pull request #753 from caktus/950801-translation-bar

[Fix Bug 950801] translation bar (take 2)
[Bug 950801] Fix alternate url output
Merge pull request #754 from Sancus/fixalternateurls

[Bug 950801] Fix alternate url output
[Bug 952601] move revision file update before checkin and deploy