JavaScript resize functions fire when they shouldn't

[miken32]

In edit.js the functions resizeMouseUp() and resizeMouseDown() are firing in response to context menu right clicks. The fix is simple, for both functions. Add near the top of the functions:

if (event.button > 0)
  return true;

In particular, resizeMouseUp() triggers a save of the map on the server side, but is doing no checking on the values. This was causing problems for us, with NaN getting written into the width and height properties of textboxes, breaking the entire map.