[forms] fix form_needs_multipart implementation
problem
-------
The current implementation of form_needs_multipart goes down
recursively in all inlined forms to check if one of them needs
a multipart enctype.
If we have a relation definition as X part_of X, the previous
implementation potentially lead to an infinite recursion
# some entities have been added before schema entities, fix the 'is' and
# 'is_instance_of' relations
for rtype in ('is', 'is_instance_of'):
sql('INSERT INTO %s_relation '
'SELECT X.eid, ET.cw_eid FROM entities as X, cw_CWEType as ET '
'WHERE X.type=ET.cw_name AND NOT EXISTS('
' SELECT 1 from is_relation '
' WHERE eid_from=X.eid AND eid_to=ET.cw_eid)' % rtype)