RFR: Mailing list filter rule generator / verifier [v4]

[Robin Westberg]

> Hi all,
> 
> Please review this change that introduces the "mlrules" command, which can be used to generate and verify mailing list
> filter rules for the jdk/jdk family of development mailing lists. These filter rules can be used by the Skara bots when
> figuring out on which list(s) a jdk pull request should be reviewed.  The idea is that this command can be used by
> knowledgeable OpenJDK developers to help improve the quality of the filter rules that will eventually end up being used
> when the jdk repository starts using pull requests. Examples of usage, together with an initial version of these filter
> rules, will be posted separately.  Best regards, Robin

Robin Westberg has updated the pull request incrementally with three additional commits since the last revision:

 - Updated after review
 - Apply suggestions from code review
   
   Co-authored-by: Erik Duveblad <erik.helin at oracle.com>
 - Update cli/src/main/java/org/openjdk/skara/cli/GitDebug.java
   
   Co-authored-by: Erik Duveblad <erik.helin at oracle.com>

-------------

Changes:
  - all: https://git.openjdk.java.net/skara/pull/733/files
  - new: https://git.openjdk.java.net/skara/pull/733/files/ef12979f..ff1ec229

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=skara&pr=733&range=03
 - incr: https://webrevs.openjdk.java.net/?repo=skara&pr=733&range=02-03

  Stats: 116 lines in 4 files changed: 57 ins; 57 del; 2 mod
  Patch: https://git.openjdk.java.net/skara/pull/733.diff
  Fetch: git fetch https://git.openjdk.java.net/skara pull/733/head:pull/733

PR: https://git.openjdk.java.net/skara/pull/733