Update valid source extensions (bug 1050583)
Merge pull request #200 from yohanboniface/bug-1050583-update-source-extensions

Update valid source extensions (bug 1050583)
Prepare stage and prod settings for staticfiles migration (bug 1013865)
Merge pull request #201 from yohanboniface/bug-1013865-staticfiles-fixes

Prepare stage and prod settings for staticfiles migration (bug 1013865)