Extend yml syntax for only and except to support specifying repository path
This allows to limit execution of jobs to specific repository.
For example:
```yaml
job:
only:
- branches@gitlab-org/gitlab-ce
except:
- master@gitlab-org/gitlab-ce
```
The above will run `job` for all branches on `gitlab-org/gitlab-ce`, except master.
@dzaporozhets @JobV @vsizov Please review.
See merge request !1720
86c0d8d289