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
Fix install script behind proxies where the default keyserver port is
not allowed.
This mirrors changes to the url in various cookbooks.
Issue TA141