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.
