Added a new driver category for DSKY (Display/Keypad) devices. Existing DSKY devices were converted into drivers ICM and PKD. These devices were previously DSKY and DSKYNG.
This removes substantial code duplication and recovers significant space in romldr and dbgmon.
- Modified the Disk Device function call (DIODEVICE) to provide new attributes related to disk size and removability.
- Leveraged API change to allow handling drive assignment differently depending on ATAPI vs. ATA interface.
- Added ability to enable VGARC and front panel in default config without I/O conflicts (does **not** support having both types of hardware present at the same time).
- Fixed documentation error in issue #345 reported by @MorfeoMatrixx.
