changed mapcube._maps to mapcube.maps
moved coalignment functionality to the image module.  Hooked up the coalignment function to the mapcube object
removed coalign mapcube function from util. all this functionality is now in image
first attempt at implementing the mapcube coalignment as a method of mapcube
added in template selection
Merge pull request #899 from wafels/ji_image_alignment

First cut at a mapcube coalignment algorithm