8181917: Refactor UL LogStreams to avoid using resource area
Reviewed-by: ehelin, mlarsson

8152632: Rename LogHandle(...) to Log(...)
Reviewed-by: brutisso, mlarsson, rprotacio

8151603: Use error stream instead of tty for logging before ShouldNotReachHere()
Reviewed-by: mgerdin, sjohanss

8145092: Use Unified Logging for the GC logging
Summary: JEP-271. VM changes contributed by brutisso, test changes contributed by david.
Reviewed-by: sjohanss, david, brutisso
Contributed-by: bengt.rutisson@oracle.com, david.lindholm@oralce.com

8140424: don't prefix developer and notproduct flag variables with CONST_ in product builds
Reviewed-by: goetz, stefank

8077842: Remove the level parameter passed around in GenCollectedHeap
Reviewed-by: kbarrett, mgerdin

8079792: GC directory structure cleanup
Reviewed-by: brutisso, stefank, david