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>
The offsets are giving the indentation to show the titles a bit to the right of the 'Ongoing submissions'. Without it would look like:

![image](https://cloud.githubusercontent.com/assets/580727/4268342/104bb54c-3cad-11e4-9c8f-397861544d5f.png)

With smaller viewport it looks quite good, only the New Submission button does not wrap to the next line properly, will do now.

So what was the benefit of removing the offsets?