Fix issue when developers are able to push to protected branch

When that branch contain a '/' in the branch name.
Fix for git over ssh
Merge branch 'master' of github.com:gitlabhq/gitlab-shell
GitLab shell up to 1.7.1
Execute command directly without using shell
   use Shellwords.shellwords for splitting origin_cmd instead of .split(' ')
More detailed warning about symlinks in repos_path
Merge pull request #94 from f0k/improve-symlink-warning

More detailed warning about symlinks in repos_path
Merge pull request #87 from bobot/master

Execute command directly without using shell
Version up to 1.7.2
Use Kernel#open to append lines to authorized_keys
Merge branch 'puts_instead_of_echo' of /home/git/repositories/gitlab/gitlab-shell
Version 1.7.3
Refactor hook creation in GitlabProjects
Bypass the shell in GitlabProjects
Merge branch 'refactor_gitlab_projects' of /home/git/repositories/gitlab/gitlab-shell
Version 1.7.4

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
Remove sed invocation from GitlabKeys
Use Ruby instead of the Bourne shell
More file writing tests for GitlabKeys
Remove chdirs from GitlabProjects
Merge branch 'clean_up_fork_and_import' of /home/git/repositories/gitlab/gitlab-shell