Split newforms tests

[leosoto <leo.soto@…>]

tests/regressiontests/forms/{tests.py,localflavor.py} are too big for Jython, where exists a limit of 32KB for the length of string literals.

And, IMO, they are too big for humans too.

[leosoto <leo.soto@…>]

[The patch size is more than 256KBytes, so trac don't let me attach it here.]

​http://www.leosoto.com/split_newforms_tests2.patch splits localflavors tests into its own directory (one file per flavor) and form tests into four files: widgets, fields, forms and extras.

As widgets.py and forms.py strings were still above 32KBytes, and I didn't knew a good criteria to split them more, string concatenation was used to avoid problems with Jython.

[Jacob]

(In [6379]) Fixed #5546: split form unit tests into manageable chunks. This isn't a perfect fix since the chunks aren't yet autodiscovered, but that shouldn't prevent checking this in. Thanks, Leo Soto.