enable heat in grenade

this enables heat in the grenade jobs. Because we need to explicitly
tell tempest what services to test, this doesn't actually test
heat (that will depend on additional grenade changes).

This is therefore a largely no-op change in normal runs which will
make it possible for the heat team to add real grenade support.

Change-Id: I6cfb2e4abf43abf91f96e85e82fcdd1fee3f9470
Support syslogs on Fedora

Use a timestamp and journalctl on Fedora to get the clean syslog logs
from the start of the run

Change-Id: Id931ffdb1013dc9368aaae580cd6270b4492c339
Merge "enable heat in grenade"
Merge "Support syslogs on Fedora"
Remove rename call in log cleanup

It turns out "rename" is not portable between Ubuntu & Fedora.
Replace the rename calls with equivalent find/mv combinations which
should be portable everywhere.

There is a slight reorganization here to make things hopefully
clearer:

 - consolidate a separate chown done for $BASE/logs/etc into the
   chown -R for it's parent directory
 - add a comment explaining why we're renaming
 - catch all .log files to rename (in old/new/grenade/etc) with one
   global find statement over $BASE/logs
 - then do more specific renames of files in known subdirectories

Change-Id: Ia6466ed34323ab00b4d01ca928c66d2ea2fb3092
fix grenade branch selection

the grenade branch selection ignored the ability to do branch
override in jobs, as such wasn't correctly enforcing things on
branchless tempest. Use OVERRIDE_ZUUL_BRANCH earlier in grenade
branch selection to prevent us from landing tempest tests that
will break grenade upgrades on stable/icehouse.

Change-Id: I55fa11f685fb33580835ffbad34eb7fb140f7e75
Merge "Remove rename call in log cleanup"