Inject username on all page and simplify template arguments
Add a first version and include it on all templates

This allows us to put the version in the footer of the pages
Add method to retrieve someone's context and display them in the profile page
Remove the un-used template_arguments function
Fix the Context.by_user query by joining with the right tables
Fix the index page as we do not use anymore the template_arguments function
More fixes to the templates to use `username` and check for g.fas_user instead of fas_user
Merge pull request #6 from fedora-infra/pingou

Global variables for all templates and add a first version