update 'recently used' list while creating screenshot

yeah, I've used zenity some time ago to invoke gimp/ompldr, but:
* I just leave shots in ~/shots untouched most of the time, so it would be really annoying to hit Esc every time I do a shot
* using 'recently used' bookmark in GTK open dialog in an already opened gimp is much faster invoking term or notion prompt and do a lot of type like "gimp sh<tab>/2013-" (oh, what's the day is it today?) "01-19-<tab>" (damn) "12<tab>" (damn!) "3<tab><enter>"

this commit also produces .bin directory initially intended to be git-managed separately
add various .bin scripts

* amix: change volume level or (un)mute and show current level in a pop-up. used in .xbindkeysrc
* notify-send: dzen2 powered notification script. used in amix
* youtube: wraps youtube-dl so it downloads clips faster (using aria2)
isX tool used in .xinitrc