NEXUS-6179: Port to master

PR for 2.7 ported to master
https://github.com/sonatype/nexus-oss/pull/287
NEXUS-6179: Added some spice to redirection strategy

Made it log redirections too to outbound log, and also emit
some info about peculiarities, that might mean you have
security or performance issues.
Merge pull request #293 from sonatype/NEXUS-6179-redirect-port

NEXUS-6179: Port to master