The Image I/O API supports automatic discovery of image format plug-ins
on system and application classpath
Currently the Image I/O API searches the application classpath only when
application code calls ImageIO.scanForPlugins.
This was motivated by a concern that in some applet sceanrios this may trigger
premature downloading of jar files.
A user of the API strongly requests that this policy be changed as complete
automatic plug-in discovery is a key part of the API