Moved logic to mixin to always force the widget if not in kwargs. Cleaner subclassing.
Merge pull request #4 from trojjer/master

Moved logic to mixin to always force the widget if not in kwargs.
Renamed test form.
Renamed form class in test
New skeleton fields in TestForm (need definition). Amended README.
Description of field_names argument.
More README fixes. Better comments for widget mixin.
Another README path fix...
Created abstract MappedWidgetMixinBase class to identify subclassed Widgets. Allows for different logic for widgets that don't extend TextInput, in separate mixins.
Commented out undefined fields.
Put the IntegerField back in TestForm
Started on BooleanField and NullBooleanField with MappedCheckboxInput
Better checking of form errors for expected fields
Separate BooleanTestForm for BooleanFields. Need to revisit NullBooleanField, as the Django widget uses NullBooleanSelect for this.
Created common MappedWidgetMixinBase._get_mapped_field_value method
Implemented DateTimeField
Refined DateTimeField tests. Implemented DecimalField.
FloatField.
Check for expected form.errors length
EmailField