update sizer for wx scroll area
remove hack around hug_* and size hints
make layout of nested containers more intuitive

This commit virtually eliminates the need to use size hint constraints
on a container. A child container now contributes constraints to its
parent concerning its minimum and maximum size. This makes nested
containers work the same with and without the shared_layout flag,
provided constraints dont cross container boundaries.
remove layout tweaks which are no longer needed
only compute max size for floating dock items

This forces the dock item to expand when docked, irrespective of dock
widget's constraints. This is the only really sane behavior since the
dock area should alway be filled.
update container min/max size handling

This updates the min/max size handling to only update the sizes of the
widget when it's ancestor is not a container. When it has an ancestor
container, the ancestor layout manager must be the ultimate authority on
min/max size, not the toolkit.
update default size hint constraints

the settings for size hint are no longer needed with the new layout
updates.
tweak task dialog for layout updates

this tweaks the size hint constraints and default constraints for the
task dialogs so that they continue to have the same user-facing layout
behavior when run against the new layout updates.
update the layout manager to support geometry constraints

this adds support to the layout manager to support boundary constraints
on a widget in addition to size hint constraints
update backend constraints widgets for boundary constraints
update backend containers for geometry constraints
update geometry guard naming
update geometry guard naming
update the dynamic fields example for layout updates
remove hug_height declarations which are no longer needed
pep8 formatting
remove hug declarations which are no longer required
more appropriate constraint weight
remove unnecessary hug declarations
remove unnecessary hug declaration