Like GitHub, show a shortcut path of the directory whoes ancestors have only one child directory.
Release TreeWalk in recuresive function.
(refs #490)Set HEAD ref when saved default branch

GitBucket allows user to configure default branch in the repository.
But it's only affect repository viewer in the GitBucekt world.
This change set default branch in the Git world.
Fix Warnings
(refs #487) split diff is available
(refs #483)Fix link in markdown
Merge pull request #491 from mrkm4ntr/myBranch

Change to show a shortcut path of the directory whose ancestors have only one child directory.
Fix client side validation error
(refs #453)Fix "Test Hook" behavior
Update slick version.