* New keybind: 'v' to open a new Viewport in the Level Editor.
* New keybind: Backspace to close the topmost UI window,
and Shift+Backspace to close them all.
* Zoom has graduated out of experimental feature status. Still a bit
buggy but workable.
* Viewport windows now copy the Tool and BrushSize of the toplevel
editor, so drawing in and out of viewports works well.
* Viewport window UI improved: buttons to grow or shrink the window
size, refresh the actors, etc.
In the Level Editor, the "Level->New viewport" menu opens a window with
its own view into your level. You can open as many viewports as you
want.
* Mouse over a viewport and the arrow keys scroll that canvas instead of
the main editor canvas!
* You can draw inside the viewports! A selectbox to choose the tool to
draw with. No palette or thickness support yet!
* The actors are installed as-is when the viewport is created and it
doesn't show any changes to actors after. Make a new viewport for a
refreshed view.
* Strokes committed inside the viewport show up in the main editor (and
in other viewports), and vice versa. The viewports accurately track
changes to the level's colors, just not the actors.
* Fun feature to load a DIFFERENT level inside of the viewport! Editing
that level doesn't save changes or anything.
