ImageComposeScene unnecessarily initializes JVM GUI Head

[jimgoog]

Probably ImageComposeScene shouldn't initialize the JVM GUI Head (eg Swing/AWT). You can reproduce on Mac OSX where running the code below will cause a JVM Application icon to appear in the dock and become focusable as a real application. This is especially frustrating when forking hundreds of processes to run unit tests in parallel in isolated JVMs.

fun main() {
    ImageComposeScene(50, 50) {}.close()
}