mds/handler.c, mds/mds_reint.c: fixup the ext3 MDS code a bit to build on

	the older 2.4.9 kernel (i_blkbits does not exist there), and add
	in the missing fixup for i_diskblocks
ALL: add in test framework for simulating errors, dropped packets, etc.
	does not yet integrate with the ext3 on-disk error interface