* Re-sync with Ubuntu.
* New upstream release:
  - Dropped patches for ZOOKEEPER-1403 and ZOOKEEPER-1431; included upstream.
  - Refreshed all other patches.
* d/{watch,orig-tar.sh,README.source}: Repack upstream tarball using uscan
  to ease new upstream releases.
* d/control: Version debhelper (>= 9~).
* d/rules: Refactor contrib builds to use properties file.
* d/ant.properties: Collate properties for contrib builds ensuring that
  bytecode built is backwards compatible.