update the guide icons to remove rounded edges
Add a utils module with a style repolish function
Add 1px darker border on floating dock windows
Code cleanup and add "floating" dynamic property

Move the maximize testing to a more appropriate place.

Add a "floating" dynamic property which is true when the container is a
free floating window. The style is repolished when it is set to allows
styling from a stylesheet.
update the handling of floating items.

Move floating items into a separate list on the docklayout. This way is
easier to understand and easier to code against.
Update layout handling

Update the manager to work with the new docklayout semantics.

Ensure that a maximized dock item is restored before redocking a
floating dock area.
put the onus of closing the window on the dock manager
Remove the destroy method

The dock manager is responsible for cleaning up dock frames.
Put the onus of closing the container on the manager
update close handling for dock frames

This updates the dock manager to handle the logic for closing floating
dock frames. This updates makes is easier to control the order of
destruction of widgets and mitigate the possibilities for segfaults in
the edge cases.