Add a status field in the pull-request table of the database
Let the pull-request view inherit from repo_master and display its status
Add a get_pull_requests method in the internal API to query the pull_request table
Add a close_pull_request API method to change the status of a pull-request to False
Add endpoint listing all the opened pull-request for a project or fork
Add in the project menu a link to see the pull-requests of the project or fork
Add logic to merge pull-requests from a fork into a project
Fix the menu to high-light 'Pull-requests' when it is asked to do so
Committing the changes in the database might help making them stable
Add a back reference from the project to its forks
Add page listing all the forks of a project