diskimage.device update and plugin SDK

Since v52.28 diskimage.device has a quite flexible plugin system. F.e. plugins are tried in order of priority much like with the datatypes system. Also they can quite easily be compiled into the .device as "builtin" plugins if this is wanted (assuming you have access to the device source code).

If there is any interest in this I could release the necessary header files as well as the sources to a couple of plugins as examples (XPK I think as well as generic, DMG and/or CISO).

The "generic" plugin is ATM the only builtin plugin and has support for several uncompressed disk image formats. It has priority -128 which means that it is used as a fallback when nothing else recognises the file.

Also for those who downloaded the initial 52.29 release I have uploaded a new archive to OS4Depot with a newer DMG plugin which should fix some issues with it.

@salass00

thanks for this wonderfull peace of software !

@salass00

you code so much that you forget to eat!
you look VERY skinny in that picture! O_O
Other than that, keep on ruling!