add transport mode and vehicle, models and views
make mode and vehicle translatable, add POT
add doc to transport_information
fix typo in README
use relative imports
tighten permissions of transport mode/vehicle

It is not sensible information, so I am giving anyone the right to read
and purchase managers the right to do anything.
Merge pull request #12 from lepistone/transport_information

add transport mode and vehicle, models and views