Merge branches/log-publishToNewObserver-tests-7710


git-svn-id: svn://svn.twistedmatrix.com/svn/Twisted/branches/log-booyah-6750-5@43463 bbbe8e31-12d6-0310-92fd-ac37d47ddeeb
Merge from #7596:
 * r43054 (copy old time to new log_time)
 * r43088, r43090 and r43095 (tests for timestamp in output in old logging system)
 * r43091 (LegacyLogObserverWrapper should provide time and system)
 * r43092 (restores timestamps)


git-svn-id: svn://svn.twistedmatrix.com/svn/Twisted/branches/log-booyah-6750-5@43464 bbbe8e31-12d6-0310-92fd-ac37d47ddeeb
Revert r43464; this is where the Py3 regression entered.

git-svn-id: svn://svn.twistedmatrix.com/svn/Twisted/branches/log-booyah-6750-5@43468 bbbe8e31-12d6-0310-92fd-ac37d47ddeeb
Branch for #7711

git-svn-id: svn://svn.twistedmatrix.com/svn/Twisted/branches/log-timestamps-7711@43472 bbbe8e31-12d6-0310-92fd-ac37d47ddeeb