[Gluster-infra] Created a new jenkins-ssh-slaves-plugin repository on GitHub

[Niels de Vos]

https://github.com/gluster/jenkins-ssh-slaves-plugin has been created
under the Gluster organisation on GitHub. This repository will be used
to forward port a feature for the ssh-slaves plugin for Jenkins. The
feature adds the option to execute a command/script before Jenkins
starts a job on a slave, and a command/script when the slave should go
offline. Paylogic implemented this last year, but it never got included
upstream. We can use it as is, but of course we try to follow "upstream
first wherever we can".

This would enable us to save quite some uptime hours of the VMs in
Rackspace, and reduce our bill.

The feature will be based on this pull request:

    https://github.com/jenkinsci/ssh-slaves-plugin/pull/16

Gaurav expressed interest, and will have a go at it first, THANKS!!!

Niels