tagging SIRF-Superbuild and SIRF

[KrisThielemans]

@paskino suggests to tag the SIRF-Superbuild as CIL has moved on. We're not ready to tag SIRF 3.0 of course. This means that our tags will be out-of-sync. It's undesirable but seems unavoidable at some stages. I suggest that we try to keep major versions synced, and do our best to release both more often such that it's easier to keep things in sync.

However, as the update mechanism in https://github.com/SyneRBI/SyneRBI_VM/ by default tries to get the latest version of the SIRF-Superbuild, we need to be sure that this update will work ok. More than likely it will need changes to the VM as well...

[KrisThielemans]

closing as out-of-date