"Swapd" is a daemon that watches free memory and manages swap files. If free
memory drops too low, additional swap files are created. Additionally, if there
is too much free memory, swap files are deactivated and disk space may be
reclaimed.

"Linux swapd" (https://sourceforge.net/projects/swapd/) didn't work very well,
but the idea was good.  I started making a version that would work and
would also be somewhat portable.  It currently compiles on Linux and FreeBSD,
but requires `libstatgrab' (http://www.i-scream.org/libstatgrab/) to work on
platforms that don't have /proc/meminfo (i.e., platforms that aren't Linux).