Do not assume contrail-controller and support for parallel build - Certain rules were looking for version.info in controller/src dir,   and this does not work for some sandbox configurations when   controller/ is not present. - The mechanism for getting hash value of controller's HEAD was   silently producing incorrect information. - Wrap both up in a function that can be used by others. - Add preliminary support for parallel build.
Do not assume contrail-controller and support for parallel build
- Certain rules were looking for version.info in controller/src dir,
  and this does not work for some sandbox configurations when
  controller/ is not present.
- The mechanism for getting hash value of controller's HEAD was
  silently producing incorrect information.
- Wrap both up in a function that can be used by others.
- Add preliminary support for parallel build.

Change-Id: If99a0564f90e42423d357bbe60100f9b7723e8ee

dirkmueller/contrail-build