Set sort parameters for fetching issues and comments
Base of the front app with 4 sub-apps

- dashboard
- issues
- workflow
- timeline
Namespace front urls and move repository_urls in front.urls
Add repositories and main views in the context.
Load models from front, not core, and add links for repositories
Context name of current repository is now "current_repository"
Move repository stuff in front/repository
Add a templates tree for front.repository
Test to display issues
Include boostrap and use it for headers
Display three panels for the "issues" page
Display assignees and labels in the left column of the issues page