Javadoc
BROOKLYN-71: DelegateSecurityProvider listens to property changes

Reloads the provider when notified and forces existing sessions to
reauthenticate.
Split rest request filter logic up

* Rest API logging much more limited: GET/HEAD logged at trace, others
  and errors at debug.
* Adds brooklyn.rest.filter package.
This closes #218

* github/pr/218:
  Split rest request filter logic up
  BROOKLYN-71: DelegateSecurityProvider listens to property changes
  Javadoc