• service table: added control proc member to allow Jemm to call out on
  certain events; currently "device_reboot_notify" is the only call-out.
• Simulate_Int: call an installed v86 hook proc before running the INT.
• JemmEx, XMS AH=0Eh: invalid handle returned if size > 65535 kB; this is
  MS Himem compatible.
• JLMs Reboot & FastBoot added.
• fixed debug displays in 16-bit part.