Use fields parameter in forms.

Don't use include, there is no such thing.

Don't use exclude, it is dangerous, the form may allow fields not shown
by the HTML form template.

Change-Id: Ie6eb74135923156e915ee18bacd4202b8521a4ed
Don't show group on institute page.

It confuses the users. If group is not set on initial creation of a
form, it will be automatically created.

However the form field required the group be set before the form can be
submitted, which in turn requires the group already exist.

Change-Id: I6a4f82bac6599d59c74003379540323409a60ff9