Designer: First pass at managed layout, with simple form wizard

[Randall Whitman]

bzr-949:  First pass at managed layout, with simple form wizard.

* Grid generated well (t06a-20110603g.gfd)
* Labels-to-Left generated well (t06a-20110603i.gfd)
* Labels-above current is laying out entries horizontally (t06a-20110603j.gfd),
  whereas designer-0.5 laid them out vertically (t054-labels-above.gfd) ...
  Is there an attribute (style?) that we can give an entry to tell
    <entry label="someLabel" ...>
  to display the label above rather than left-of the entry,
  rather than using either separate label elements, or hbox in vbox
  (manual-label-above.gfd)?
* Display of form elements in Designer canvas, is broken again -
  PagePainter/skins/default.py EntryWidget, LabelWidget - cf
  using Forms API to ensure displaying same in Forms & Designer.
* Still getting layout xmlns:Char="GNUe:Layout:Char" rather than
  xmlns:s="GNUe:Layout:Sizer", not sure why.
* Need to mind FormBuilder as well as Simple.

Randall Whitman <http://whizman.com>

t054-labels-above.gfd
Description: D-0.5 labels above

t06a-20110603j.gfd
Description: D-bzr labels above

manual-label-above.gfd
Description: Managed Label Above - manual GFD

t06a-20110603i.gfd
Description: D-bzr labels to left

t06a-20110603g.gfd
Description: D-bzr grid