v0.5.6 (2009-09-25): Add an O_DIRECT toggle, destructive write mode, and
increase default buffer size to 32M.
v0.5.5 (2009-01-12): Tidy up Makefile (adamg@pld-linux.org)
v0.5.4 (2008-11-23): Fix tagging and tarball making
v0.5.3 (2008-11-21): Implement io and cpu priority
v0.5.1 (2006-02-18): Fix some of the strings to make more sense.
v0.5.0 (2006-02-17): Total rewrite of the program to have a tighter inner loop
and to lock the read buffer into memory via mlock().  Also take out several
options that were never used and use CLOCK_MONOTONIC for (hopefully) better
accuracy.
