Support oslo-incubator in final release scripts

Add support for oslo-incubator in rccut.sh and rcdelivery.sh.
Oslo-incubator does not get tarballs generated or uploaded, so we skip
appropriate parts of the script. It also introduces a difference between
LP project name ("oslo") and git repo ("oslo-incubator") that the script
takes into account.

Change-Id: I8fb9f37b6719a8f9187ee12267a687d09e463dae