Only cover the widget types that were recently refactored.
A few conventions are set as followed:
* Textwidth is preferably 80, since the whole point of tiling windows
is to be able to view more pane of codes
* Standard, 3rd-party and local require should be grouped together
* Closing parentheses should not be on lines by themselves
There should be a style guide to clarify these.
* 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