• Assorted small fixes so that form comply to conventions
• Minimal fixes of invalid html
• make mixin usable in type definition

The context is I was working on a custom configurator involving some matrixboxs, so I needed a simple business configuration item just to store the matrix result. This was possible with mixin, I just made a portal type based on Item class, enabling mxins for Matrix and BusinessConfiguratorItem and I did not have to define a class ( not sure this is really better ).

Then the matrixbox was not rendering properly, because browser was confused by the broken html and build a "different DOM" and selectors did not apply. This is what configurator: fix (a bit) invalid HTML addresses.

While doing this, fix some minor problems found with forms.