Redesign of hbase98 job pipelines

Previous hbase98 layout did not work for daily (timer) jobs.
Timer events don't have a branch, so branch-restricted jobs don't run.

Even changing cdh4.4 jobs to match all branches except hbase98 does not
work because NullChange objects do not have a branch attribute and do
not attempt comparison.

So, instead of restricting jobs to specific branches, now we'll restrict
check/gate pipeline events to particular branches. This forces us to create
additional pipelines for the transition time, which was the original thought
anyway.

Not supporting an check-full-hbase98 pipeline at this time. It can be added
if needed.

Change-Id: I90362b13faa7457ef4a0931b9a1d18d4cd47f70f