A utility to apply POSIX_FADV_DONTNEED to a specified file.

This was primarily written to workaround a problem with MySQL on Linux Kernels before 2.6.28 where the filesyste cache would fail to honour vm.swappiness=0. This could cause extreme swap usage with large InnoDB log files.

Inspired by https://github.com/yoshinorim/unmap_mysql_logs and http://code.google.com/p/linux-ftools/.