deposit: rename /deposit to /submit

* Renames all appearances of deposit for submit.

* Adds BLUEPRINTS_URL_PREFIXES to modify deposit url prefix.

* NOTE In order to modify the breadcrum of deposit module and useful
  for the future, introduces Babel configuration to allow translation
  of strings in the overlay. In development mode, to see the translated
  strings, run $ python setup.py compile_catalog
  Translation catalog is compiled automatically if you install
  using $ python setup.py install

Signed-off-by: Javier Martin Montull <javier.martin.montull@cern.ch>
You could use `col-centered` class from Bootstrap in order to center an element without using offsets that might break the mobile display.

But seeing the attached screenshot maybe we could benefit the offsets and do a 2-column layout to display also the `Past Submissions` as a user won't scroll down to check those. It's one way we can tackle the issue of not having pagination for now. Just thinking out loud here.