The z-probe feature in Easel will work with the original X-Carve. You need to run the machine setup under the “Machine” menu. It will get to a page asking if you have a z-probe. If you do have one that works with other software it should work with Easel. Be sure to select the advanced option on the z-probe setup page, so you can enter the height of your device (if not using the one sold by Inventables).
You will need to make sure your arduino is updated to 1.0.