Make ICNS generation pure java

[choffmeister]

The task of converting an image into an ICNS file should be written in java. According to http://en.wikipedia.org/wiki/Apple_Icon_Image_format it should be not that hard. The format seems pretty simple. Just some header bytes + PNG image content.

This makes the task runnable an systems where sips is not present.

[choffmeister]

At https://github.com/choffmeister/icnsgen there is a simple POC project. Works very well. Also embeds the icon in multiple resolutions.

To test just clone the project and sbt test. The output file name of the .icns file is printed to the console.

[Sciss]

Which would be a system where the Jar Bundler is present but sips is not?

In any case, I will have a look at your icnsgen project when I find time. Embedding that conversion of course would be good.

[choffmeister]

Why not include the AppStub as resource in the plugin? Whould that make the task completely system independent?

[Sciss]

Yes, that would be possible of course. I had refrained from it so far because almost inevitably there will be PITA with Apple's licenses and copyrights. But maybe it's not that problematic, it just has to be investigated.