Merge pull request #159 from hughsaunders/sprint

Merged automatically by jenkins after successful gate test
Add ability to specify Git User/Branch for cloning on Dev Install
Default to sprint branch if specified branch doesn't exist
Merge pull request #161 from andymcc/sprint

Merged automatically by jenkins after successful gate test
Merge pull request #162 from andymcc/sprint

Merged automatically by jenkins after successful gate test
Kill Agent processes on RERUN
May aswell kill the opencenter server at the same time as the agents
Merge pull request #163 from andymcc/sprint

Merged automatically by jenkins after successful gate test
Fix error message if apt-key isn't added appropriately
Merge pull request #164 from andymcc/sprint

Merged automatically by jenkins after successful gate test
experimenting with cloning
tweak vagrant file