Add JSch jar for JGit Transport dependency
Use remote branch name instead of id in Repository#copy_branch_from_repo
Flush & release
Use and improve Publication#head
Use full "refs/heads/" string for branch in updateRef call, fixes fetch
Use PersonIdent in commit call
Revert Publication#head hack
Remove unused JGitTree#write! method
Move JGitTree into separate JGit module/file