wall drawing: draw points dragging the cursor, filter them by min-distance threshold
and join them (could use http://jsfiddle.net/pxemt/2/)
wall modifiers, ex. cut/divide at point, join walls, etc...
set zoom 100% button [mod+1]
fit map to screen button [mod+0]
history undo/redo [mod+z]/[mod+shift+z]
...
Notes:
The y axis is inverted: in AA the y value is higher on top,
while in browser the y value is higher on bottom.
By now vectron starts displaying the map center on the top-left corner of the screen.
To respect the maps standard, an empty map should start with the center point on the bottom-left corner.