* used memory (values 1 and 2) are: everything but free+cache
* laundry is counted as freeable, but not free.
** "notfreeable memory" (values 11 and 12) are: active+inactive+wired
* removes unused variables
* enhances one-character-variables for better readabilitiy
* fixes calculation errors
** used memory: active, inactive, and wired
** available memory: cached, laundry, and free
see https://wiki.freebsd.org/Memory for more information
mutlusun
Andreas Geisenhainer