Don't keep a local copy of the binary image data.

We were loading the image data into the composed Horde_Image object
AND keeping a cached copy of it (along with any other views of the
image that were loaded in this page view) in the Ansel_Image object.
There is no longer any need for that. Only load the image into
the Horde_Image object object directly and save on memory.

Next up, take advantage of Horde_Image's stream capabilities. Mostly
benificial when using a backend like ImageMagick when the image data
is stored in temporary files instead of being kept in memory like in
GD or Imagick drivers.