* Added `BoxSize()` to Widget that reports the full box size including
borders and margin.
* The Frame uses the `BoxSize()` of widgets to position them.
Reintroduces some padding issues (boxes on the GUI Test stick out of
bounds a bit) but is on the right track.
* Renamed `Padding` to `Margin` on the Widget object, since the Margin
is taken into consideration along with Outline and Border in computing
the widget's BoxSize.
* Restructured the Label widget to take a Text or TextVariable property
and the font settings (render.Text) are in a new `Font` property.
Known bugs:
* The Pixel format in the Grid has DX and DY attributes and
it wreaks havoc on collision detection in Play Mode when you
come straight from the editor. Reloading the map from disk to
play is OK cuz it lacks these attrs.
Implements the dev console in-game with various commands to start out
with.
Press the Enter key to show or hide the console. Commands supported:
new
Start a new map in Edit Mode.
save [filename.json]
Save the current map to disk. Filename is required unless you
have saved recently.
edit filename.json
Open a map from disk in Edit Mode.
play filename.json
Play a map from disk in Play Mode.
