DOC: Minor changes to docs and boosting now version for 2.3.0 release
Merge branch 'master' of github.com:PyMVPA/PyMVPA

* 'master' of github.com:PyMVPA/PyMVPA:
  BF: Adhoc fix to let exported NIfTI files have a sane display range
Adjusting changelog
BF: hyperplane_demo -- plotting of colorbar should happen together with imshow