"There are a couple of tools such as pencil/stamp mode, eraser, and rectangle. Note the rectangle tool can automatically nine-patch your tiles if you have a 3x3 selection, making it quick to draw certain kinds of boxes in the tilemap."
<img src="https://dl.dropboxusercontent.com/u/666516/rectangleselect9patch.png" border="0">
And a Capcapx example.
Edit:
It doesn't do 4 sided maps.