#1 operators in rules (get_collection)

[Ricardo Acras]

didn't test other cases, but in order to '=' operator
works fine in db_hl->get_collection(...) one have to
put spaces surrounding it or it will be ignored.

Example:

'rules' => ' AND ( remessa.nota_fiscal=1 ,
remessa.cliente_id = 2') <--- will consider just
remessa.cliente_id = 2

-

'rules' => ' AND ( remessa.nota_fiscal = 1 ,
remessa.cliente_id = 2') <---- will consider both
retrictions