Also, add other social media accounts to list of places to
announce Tux Paint in RELEASE docs.
Also, list a ton more options missing from default example config file
"src/tuxpaint.conf"
Using XDG's user dir settings to determine where pictures are
stored for a user (e.g., "~/Pictures" -- used as a fallback).
May be overridden using "--exportdir".
Also, while I was updating some docs, replace references to
"Mac OS X" with "macOS", the new name of that OS these days.
Ability to disable stereo panning effect (e.g., paint brush, UI
elements sound effect feedback, etc.), useful for users with
hearing impairment in one ear, or situations where one speaker or
headphone is being used. Use "--nostereo" command-line option
or "nostereo=yes" config. file option.
PostScript printing now uses libprint to determine papersize, and scale and
position image accordingly. Thanks to Henry House.
"--papersize" option added to allow PostScript printing code to use a
different size than libpaper reports as the user's or system's default.
