This module return the total amount of free and used physical memory
in bytes in totalmem and freemem variables.

This module has been tested on Linux 3.13.0, UnixWare 7.1.2, AIX5,
OpenBSD 3.8, NetBSD 2.0.2, FreBSD 5.4, HPUX11, Solaris 9, Tru64
5.1, Irix 6.5, MacOS X 10.2 and Windows XP.

It should work on FreeBSD 4 and Windows 9X/ME/NT/200X/Vista.