Thanks Josh Kupershmidt.

JavaScript serializations of forms will sometimes render the boolean
values as the strings 'true' and 'false', in lower case. Rather than
repeat boilerplate in the JavaScript to circumvent this, it seems
reasonable to allow Django to understand the lower-case versions of the
booleans.

Makes declined or missed renames still work (but drop data).

The 'app' subpackage does not exist, should be 'app'.

Fields normally try to force the default value to a string. As
translatable strings are not valid default values for ArrayField, we can
remove this behaviour which was causing issues with some migrations.

Thanks to @schinckel for the report.

Thanks to wkschwartz for the report and to Tim for the patch.

Thanks to gmunumel and Tom Dalton for their help on the patch.

Thanks Andreas Pelme for the report.

Thanks to Tim Graham for the review.

Thanks Chow Loong Jin for the report and the initial patch.

Patch by Tim Graham. Thanks areski for the review.

Thanks Matthieu Agopian for the report.

Forward port of 999758fc from
stable/1.7.x

Also allowed overriding the default messages in subclasses of BaseValidator.

Thanks sperrygrove for initial patch.