GXemul Code2

Implementing the fsub.sss 88K instruction.

LUNA 88K TODOs.

Reasserting timer interrupts when timer register is accessed, instead of just DEasserting.

Possibly make things build on Linux with some compilers?

Minor updates.

Some systems/compilers treat ignored return value from write() as an error, not a warning.

Do not warn about all ethernet addresses starting with 0x00 (such as the LUNA-88K machine).

Adding note about failure to run Xorg due to lack of wsfb driver in OpenBSD/luna88k 6.8.

Implementing the fdiv.dss 88K instruction.

Return the d register to what it was before an exception.