Having two identical but disctinct subclasses of RealARBGColorConverter avoids
JIT de-optimization when using it for both volatile and non-volatile types.
(The non-volatile version is used for recording movies.)

Conflicts:
	core/src/main/java/net/imglib2/display/RealARGBColorConverter.java
Merge remote-tracking branch 'github/towards-spimdata' into towards-spimdata
make BigDataViewer a bit more extension friendly
Merge remote-tracking branch 'github/towards-spimdata' into towards-spimdata