Support for webhelpers optgroups
Support for webhelpers optgroups

If tags.select can produce a select that uses optgroups if its options
is a tuple or a list in the form of (value, label) where value is
also a tuple or a list.

Modifies the (value, label) permutation so that it only does a
permutation of the leaves and not the structure that generates the
optgroup.

FormAlchemy/formalchemy,FormAlchemy/formalchemy,camptocamp/formalchemy,camptocamp/formalchemy,camptocamp/formalchemy,FormAlchemy/formalchemy,camptocamp/formalchemy,FormAlchemy/formalchemy