Use gitlab_shell.path to invoke rewrite-hooks.sh

The backup restore code for repositories was assuming that gitlab-shell
is installed in /home/git/gitlab-shell. This commit changes that to use
the configuration setting from gitlab.yml that specifies the path where
gitlab-shell is installed.
 Merge branch 'backup_restore_hooks_bug' into 'master'

Fix backup/restore git hooks bug
Enable html_escape for code blocks highlighted in markdown

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
html_escape is private for rails 4.0.2 :(

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>
 Merge branch 'highlight_html_escape' into 'master'

Enable html_escape for code blocks highlighted in markdown

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/94
Merge branch 'master' of github.com:gitlabhq/gitlabhq