cleanup logging and show logs in interactive mode

see issue #413 for more info
Expose the urllib2.urlopen response as response_info in URLInputSource

Enables parsers to access response headers (such as Link headers).
Merge pull request #437 from joernhees/fix_double_2to3

disable double 2to3 in setup.py
Merge pull request #414 from RDFLib/cleanup_logging

cleanup logging and show logs in interactive mode closes #413
Merge branch 'master' into six_2to3

* master:
  Expose the urllib2.urlopen response as response_info in URLInputSource
  cleanup logging and show logs in interactive mode