Replaced copyright notice
Removed session migration create because it is already present within the migration directory
Merge pull request #2034 from tboerger/feature/copyright-notice

Replaced copyright notice with unified header
Merge pull request #2036 from tboerger/feature/migration-addition

Removed session migration create because it is already present within the migration directory
Replaced shebangs with /usr/bin/env call

This way the environment can decide which interpreter got to be used.
It's absolutly usefull if we try out other ruby versions or to use
another path for the ruby binary.
Removed locale_additions functionality

As the i18n content is now always stored within the localization files
we don't need the locale_additions anymore. And of course we don't need
this extraction methods either.
Removed the duplicated calls for proposal requests
Added copyright to generated navigation
Added single link for primary menu entries