common.sh
---------

* Clean-up REPO_DEST REPO_URL (that only seem to be used for build-sdk anymore) and QUEUE_URL. This should probably go in settings.sh since this is local to the machine. Anyway shouldn't it be hard-coded anyway since buildmaster is the only user that can clone the repository (besides admins).

* The packages versions (ILM, OIIO, etc...) should probably be set in a separate script to make it more readable.

* Compiler and compiler specific flags should be set in a separate script as well

* NATRON_RELEASE_BRANCH, NATRON_GIT_TAG etc.. should go away, they just clutter common.sh

* All installer packages names and versioning should go in installer-common.sh

settings.sh
-----------

* Instead of having NATRON_LICENSE and MKJOBS as parameters of buildmaster.sh, the settings.sh
should contain them as it already includes local, build-server dependent variables.

