Log Message:
Update memtester to 4.2.1

Changelog:
Version 4.2.1
3 October 2010
  -fix offsets/addresses were not being reported correctly in test failure
  messages.  Thanks: Anton Sergeev.

Version 4.2.0
30 July 2010
  -define _FILE_OFFSET_BITS to 64 by default in conf-cc, which causes some
  32-bit systems with larger-than-32-bit address spaces to have a 64-bit off_t,
  allowing testing of larger chunks of memory.  Thanks to Steven A. Falco for
  the suggestion.  Let me know if this definition causes problems for anyone.
  -add tests of 8-bit-wide and 16-bit-wide random writes, to enable verifying
  the correct operation of hardware.  Thanks: Dick Hollenbeck.  If these tests
  trigger unaligned access problems on your platform, you can eliminate these
  tests by removing the -DTEST_NARROW_WRITES definition from the conf-cc file.