RFR: 8157948: UL allows same log file with multiple file=

[Marcus Larsson]

Hi,

Please review the following patch to fix the issue where you could have 
the same file added twice as different log outputs in UL if it had the 
"file=" prefix or if it was quoted. Log output names are now normalized 
during log argument parsing to ensure they are always normalized when 
finding existing or adding new outputs.

Webrev:
http://cr.openjdk.java.net/~mlarsson/8157948/webrev.00/

Issue:
https://bugs.openjdk.java.net/browse/JDK-8157948

Testing:
New unit test through JPRT

Thanks,
Marcus