fdisk: sync up with some util-linux 2.31 behavior

fdisk: sync up with some util-linux 2.31 behavior

= display default is no longer in cylinders
= +sizeC is no longer supported
= add +sizeT suffix - terabytes are here
= K,M,G,T and k,m,g,t suffixes all are binary, not decimal
= +sizeM results in last sector +(size * 1Mbyte - 1), not +(size * 1Mbyte)
= fix comparison to "YES" answer for sgi/sun

function                                             old     new   delta
read_int                                             492     519     +27
fdisk_main                                          2644    2640      -4
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/1 up/down: 27/-4)              Total: 23 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>