Fixed errors in 848101bf1736d1c01eb86968e85a14c7466bb376
Fixed #15582 -- Documented how TransactionTestCase.multi_db affects fixtures.

Thanks slinkp for the suggestion.
Updated OpenLayers version from 2.11 to 2.13
Forms docs: More emphasis in 'id'  value customizability.
Fixed #21173 -- Stopped fixing format for date-based widgets at init time

Thanks Marc Tamlyn for the review.