INT 21 - Novell NetWare - TRANSACTION TRACKING SYSTEM - ABORT TRANSACTION
        AX = C703h
Return: CF clear if successful
            AL = 00h
        CF set on error
            AL = error code
                FDh transaction tracking disabled, no backout
                FEh transaction ended records locked
                FFh no explicit transaction active
Note:   this function is supported by NetWare 4.0+ and Advanced NetWare 1.0+
SeeAlso: AX=C701h,AX=C704h