INT 7F - MultiLink Advanced v1.0+ - SET TASK PRIORITY                           
	AH = 09h
	AL = priority (0-7)
Return: nothing
InstallCheck:	ensure that the interrupt vector is not pointing at segment
	  0000h, then test whether the byte at offset 0000h in the interrupt
	  handler's segment is E9h
Index:	installation check;MultiLink Advanced
SeeAlso: AH=00h"MultiLink",AH=0Ah"MultiLink"