Multiple git hooks running for the same project 

This feature allow users to create multiple git hooks in repositories that do not conflict with gitlab-shell update hook (refs #85, #71, #72, #10, #14)

A ```hook-wrapper``` script is symlinked on repository hook folder. This wrapper symlink have the same name of destination hook (eg ```update```, ```pre-commit```, ...). The hook–wrapper script on execution search for all ```[hookname]-*``` files and execute they. Exit code are reported from wrapper script.

This MR is required to add "git hook management" (refs ) feature on GitLab (already stubbed, MR in progress).