Minor classes adjustment
Update main navigation(less space used).
Some more tweaks to the main, account and context navigation.
Improve permissions hierarchy.

An administrator is a manager, a manager is a pusher, etc...
Add pusher, contributor and commiter groups.
Start managing translations.

Currently only `en` and `en_GB` to be able to have different date and
time formattings.
We need the country code in the locale name
`admin_permission` was renamed to `administrator_permission`.
Minimal support for users and groups(currently read-only).
Some more style changes, mostly "highlight" admin stuff.
Minor layout changes.