INT 2F - Novell ODI Link Support Layer (LSL.COM) - INSTALLATION CHECK

	AX = C000h
Return: AL = FFh if installed
	    DX:BX -> FAR entry point (see #02986,#02987,#02988)
	    ES:SI -> signature string "LINKSUP$"
Range:	AH=C0h to AH=FFh, selected by scanning for first free multiplex number
Note:	on return, ES = DX for LSL v1.10 and v2.05; LSL makes use of this in
	  its search for a previous installation
SeeAlso: AX=5100h,AX=C000h"NESL"