Rotate images which have an EXIF orientation tag.
Restructured the orientation fixing code.
Check if exif data is empty before checking for the orientation data.
Removed extraneous ExifTags import.
Restructured the Exif orientation handling.

* Moved logic into a resize() util function that wraps
  PIL.Image.resize().
* Added and utilized a couple utility functions for getting
  image dimensions, taking orientation into account.
Removed an extra line break.
Removed redundant calls to exif_aware_size.
We don't need to use Django 1.7's clever PIL import trick.
Added tests for exif utilities.
Need to include the JPGs that are in test data.
Added test for exif_aware_size.
Fixed test names.
Switched out the list comprehension for a dict comprehension.
Merge branch 'master' into fix/exif-orientation
Merge pull request #52 from littleweaver/fix/exif-orientation

Rotate images which have an EXIF orientation tag.