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
got rid of the need to create a whole new datacube to store the shifted data.  This should be more efficient in memory.
added in some recommendations in the coalignment method
coalignment method now returns a new mapcube
changed some comments in the clipping code
removed print statement that was used for debugging
used a try/except block to warn about missing coalignment
added import error trapping for the coalignment method
warning now appears when coalign method is attempted to be used when the required module is not present.
changing the catching of the lack of match_template: raise an ImportError error in function that requires it.
Merge pull request #904 from wafels/ji_image_alignment

got rid of the need to create a whole new datacube to store the shifted ...
Merge branch 'master' into image_alignment
Merge pull request #905 from Cadair/image_alignment

merge master into Image alignment
extra coalignment functionality
more capability to the coalignment