[fix bug 932987] Move templates to 'mozillians' app root.
[fix bug 938037] Fix image path in 500.html.
Merge pull request #718 from glogiotatidis/500error

[fix bug 938037] Fix image path in 500.html.
[Bug 741604] use names rather than numbers for external account types
[Fix Bug 741604] Add multi-website support
review fixes