Add a JavaScript binding for nanoColor

[doug-walker]

Currently OCIO is not available for use in web applications (i.e., running in a browser). This task is to add a JavaScript binding that makes it simple to use OCIO for color management in web applications.

The proposal is that this binding would only be available for nanoColor, since it is specifically targeted as a lighter weight version of OCIO that is simpler to adapt for this purpose.

More details will be forthcoming, but if people have requirements for this feature, please add a comment to this issue.