8157948: UL allows same log file with multiple file=
Reviewed-by: dholmes, rehn

8153074: UL: Show output option in VM.log jcmd
Reviewed-by: dholmes, mlarsson

8145934: Make ttyLocker equivalent for Unified Logging framework
Reviewed-by: rprotacio, stuefe, jrose

8146879: Add option for handling existing log files in UL
Reviewed-by: dsamersoff, gziemski, rehn

8145294: TestLogRotation.java triggers a race in the UL framework
Reviewed-by: sla, mgronlun

8140556: Add force rotation option to VM.log jcmd
Summary: Rotate JVM log files via jcmd
Reviewed-by: sla, mlarsson

8046148: JEP 158: Unified JVM Logging
Reviewed-by: coleenp, sla