Add documentation, might_mask(), dict-like interface for Reader.
Add documentation, might_mask(), dict-like interface for Reader.

pombredanne/python-pure-cdb,douglasbagnall/python-pure-cdb,douglasbagnall/python-pure-cdb,douglasbagnall/python-pure-cdb,pombredanne/python-pure-cdb,dw/python-pure-cdb,dw/python-pure-cdb