Kepler

I'm working on a partial solution to this one by adding editable comboboxes
for the type and units to the port dialog. I agree that combining
the dialogs might be a good idea here, but my changes will not address that
issue.

I've modified ptolemy.actor.gui.PortConfigurerDialog so that
is uses editable combo boxes for the port types and units.
The type lattices is infinite when array, matrices and records are
added, so I only have examples of those types. The types names
themselves come from constants listed in data.expr.Const.
The unit lattice is also infinite, so I'm only adding a few
category types.

Rowland Johnson said:

A combo box with all the possible values for units expressions isn't really
    possible, because, theoretically, there are an infinite number of such
    expressions. The units field of the PortConfigurerDialog should accept any
    valid units expression. Currently, a units expression that is entered via
    the PortConfigurerDialog is first parsed to determine its validity.

Maybe a combo box that contains commonly used units expressions with the
    capability to enter a units expression that isn't on the list might work.
    Different domains could each have a different list. Just figuring out what
    the domains are and the contents of each domain's list would be an
    art-form/research project in itself.
--end---
The editable combo boxes verify the values when the focus moves,
so we no longer need to pop up a separate dialog for editing the name, type
or units.

Other fixes that would be nice:
1) If the user drags in an ptolemy.data.unit.UnitSystem icon then
we should add to the units that are displayed in the combo box

2) Consider implementing a single dialog to configure the parameters
and port info.

Original Bugzilla ID was 2012