GXemul Code2

More i960 stuff, including re-adding the (so far dummy) Cyclone VH machine.

Comment about how the crosshair works on my O2.

Replacing some more exit(1) calls.

Porting over i960CA disassembly from the C++ framework.

Porting over HP700/RX details from the C++ framework, which is no longer.

Updating the TODO.

On these 32-bit architectures, do not sign-extend the PC (IP) register.

Names for RAM/ROM ranges.

Actually not implemented yet.

Working on basic RISC-V and i960 stuff. Also making all CPUs use a common routine for indicating the current PC in disassembly output. And beginning to add i960 b.out support (again).