Add metadata to Jenkins webhook url.

- Add branch and sha1 on Trigger Build
- Add branch and sha1 on RefChanged
Remove onpullrequestrescope handler from Pullrequesteventlistener

Remove onpullrequestrescope handler from Pullrequesteventlistener since
Repositorychangelistener will trigger changes on all branches.
Resolves #66.
Don't call webhook on branch delete
Temporary: Will be rewritten with configuration

- Deactivate triggering of webhook from opening and reopening of
  pull-requests.
Merge pull request #71 from loa/branch-sha1-in-jenkins-webhook

Add more metadata in Jenkins webhook and resolve multiple triggers.