* Menu item to hide or show all images
* Images: asymmetric color nodes.
* Added RBA::image::from_s for reading image back from string. Added tests.
* Added image file reader test (RBA)
* Added lyimg format for image file persistence.
* Small fix of unit tests.
* Added GSI binding for new image features and tests.
* Save and load for .lyimg formats in image properties dialog.
Matthias Köfferlein