Fixed failure with checkbox
Moved placeholder to InputField, added additional validation attrs
Added pattern attribute
Made HTML5 attributes mixins for form-fields
Merge branch 'hotfix/classifier'
Merge branch 'release/2.0.1'
Merge branch 'release/2.0.2'
Merge branch 'release/2.0.3'
Merge branch 'develop'
Merge branch 'release/2.1.1'
Merge branch 'release/2.1.2'
Merge branch 'release/2.1.4'
Merge branch 'release/2.1.4.1'
Remove specfile.
Fix up tests with valid xhtml.
Python3 support.
Merge branch 'feature/2.2' into develop
Add dep on six.
Merge branch 'feature/html5-validators' of github.com:toscawidgets/tw2.forms into feature/html5-validators

Conflicts:
	tests/test_widgets.py
	tw2/forms/widgets.py
Fix CheckBox validation to a proper boolean