* dh_python2 transition.
* changed to source format 3.0 quilt.
* added debian/pydist-overrides to assist dhp2 calculate Depends.
* debian/rules
  - changed "--with python-central" to "--with python2".
* debian/control
  - changed python-all to (>= 2.6.6-3~).
  - added python-all-dev to B-D.
  - increased debhelper to 7.0.50.
  - removed B-D on python-central.
  - increased Standards Version to 3.9.2.
  - changed XS-P-V: all to X-P-V: >= 2.5.
  - removed XB-P-V, no longer needed.