Format of sharing record:
Offset	Size	Description	)
 00h	BYTE	flag
		00h free block
		01h allocated block
		FFh end marker
 01h	WORD	size of block
 03h	BYTE	checksum of pathname (including NUL)
		if sum of ASCII values is N, checksum is (N/256 + N%256)
 04h	WORD	offset in SHARE's DS of first Record Lock Record (see #01638)
 06h	DWORD	pointer to start of system file table chain for file
 0Ah	WORD	unique sequence number
 0Ch	var	ASCIZ full pathname
Note:	not supported by DR DOS SHARE 1.1 and 2.0; will reportedly be
	  supported by Novell DOS 7
SeeAlso: #01636,#01638