These commits fix a bunch of bugs we discovered when testing our
in-house apps on real production color configurations.

* Yaml serialization fix, resource_path is updated properly
* Relative path loading works again (for FileTransform)
* Yaml output doesn't include default transform direction. (need to
generalize this not to emit default values in general)
* Fixed processing bug related to handling of null transforms
* Yaml bugfix, previously color spaces which defined the transform
"from_reference" were hosed.

js/master

8e6e90b822f21e02b055e9ef9a95e78ac88dc15f
8046c604171470c3a3b8dd31fc51a69d127371a4
e24312c91420a92158658f418e05032ad934d97f
f381144da667b388da86a8492ce28ca7e19a1a2a
c4a68d76662fb74676ac6e94b3f0abcd24c68de7
4a0063ce32c35cffb13bab77eef024971a615266

-- Jeremy