Do not turn on debug.YUI by default.
It is quite disruptive of the UI and probably rarely used.
(Note that this library has been abandoned by Yahoo!)
Workaround: mvn hpi:run -Ddebug.YUI=false
(Setting this property in a profile active by default does *not* work.)
Reverts 87c0b73.
Merge branch 'master' of github.com:jenkinsci/maven-hpi-plugin