* Change tests to make it possible to run TestGit with 1.7.2
* Make merge run on 1.7.2
* Fix tracking and staging branch name problem
* Ensure that git 1.7.2 works on tests
* ensure that there is no chance for conflicts
* Fix-up missing merge issues
* Final rm
* Ensure LFS filters run on the tests
* Do not sign commits from temp repo
* Restore tracking fetch change
* Apply suggestions from code review
* Update modules/repofiles/temp_repo.go
* extract actions on new pull request from models to pulls service
* improve code
* move code.gitea.io/gitea/modules/pull to code.gitea.io/gitea/services/pull
* fix fmt
* Rename pulls.go to pull.go
Lunny Xiao