Use BlockDataGridFieldObject for rows in a BlockDataGridField

This was probably a copy paste error from the "normal" DataGridField.
Without this the BlockDataGridFieldObject class does not make any sense
and templating it is not possible.
Filter out any auto append or template rows in updateWidgets

These are not "real" elements of the MultiWidget and confuse
the updateWidgets method if len(self.widgets) changes.
This is relevant for nested datagridfields.
Merge branch 'master' of git://github.com/collective/collective.z3cform.datagridfield
Add row parameter to aftermoverow JS event
Don't reset class attribute on cloned template row

This allows customized CSS styling for the rows. E.g. with custom
templates.
Replace row index in all template row elements

References to the row index were only replace in input elements and
certain other elements. With custom templates (possibly using the
standard widget wrapper) many more elements may contain references to
the row index. Replace the row index in all id, name, for, href and
data-fieldname attributes when cloning the template row.

To simplify the reindexing the current row index is stored in a data
attribute.
Merge branch 'master' of git://github.com/collective/collective.z3cform.datagridfield
some rst formatting
Merge branch 'master' of
git://github.com/collective/collective.z3cform.datagridfield

Conflicts:
	docs/HISTORY.txt