[docs] Add doc examples for DictReader and DictWriter (issue 20351)

[vadmium+py at gmail.com]

http://bugs.python.org/review/20351/diff/10699/Doc/library/csv.rst
File Doc/library/csv.rst (right):

http://bugs.python.org/review/20351/diff/10699/Doc/library/csv.rst#newcode166
Doc/library/csv.rst:166: Wonderful SPAM
I think the space argument to print() shouldn’t be there; print() should
already be adding the single space separator on its own. Also, making
the capitalisation agree with the DictWriter example below would be
nice.

http://bugs.python.org/review/20351/