Fixed the wrongly enforced collation field on <typeattrib> (issue #254)

Fixed collation SQL. Encoding is appended to LOCALE. (issue #255)

Fixed the wrongly used COLLATION keyword on UserType. (issue #256)
Minor fix on model export helper when showing currently validated
object.
Added an special field to columns to easily identify which relationship
generated it. (only for columns added by relationship)

Also on model widget columns tooltips shows parent rel. name and an
action was added to open the parent relationship from the column's
actions menu.