simplify morph

crap
photo.JPG appears to tested for incorrect attributes
Merge branch 'master' of git://github.com/aheckmann/gm into fix-tests
Revert "simplify morph"

This reverts commit 1a824bec1f9af533711d61aaa44045c23125c3ac.
morph: only delete temporary files when necessary
test: allow variability in image statistics
Merge pull request #138 from jonathanong/fix-tests

[WIP] Fix tests