Updated "funtoo" commit marker in "gentoo".
Overhauled "$USE" in "gentoo".

	* A full review of these was long overdue...
Added "tmux, gpm" to "gentoo".
Added additional "perl" greatness to "gentoo".
Added "mercurial" to "gentoo".
Added "pandoc" and general "markdown" to "gentoo".
Updated formatting of "@package" set in "gentoo".
Added "avahi" to "gentoo".
Added "terminology" to "gentoo".
Added "argus*, net-snmp, rrdtool" to "gentoo".