NEXUS-6183: Returned stopwatch for outbound logging purposes

As Yammer does not provide clean way to extract the
"last recorded duration" from timer or timer context in
cheap way.
NEXUS-6183: Start stopwatch

As otherwise it would do any much :)
Merge pull request #292 from sonatype/NEXUS-6183-outbound-logger-timing

NEXUS-6183: Returned stopwatch for outbound logging purposes