Remove obsolete mpd scripts. These scripts should no longer be used as their maintenance has moved to the "mpdhacks" repository. We can add that as a git submodule to achieve a similar level of convenience. Fix up all the rootmenu scripts to follow the new world order by adding a new global script that removes most of this code duplication. As the mpdmenu.pl script is the only user of the MUSIC environment variable, and it has its own fallback, let's remove the toplevel assignment of this variable too.
MPD script updates. Fix compatibility with latest perl which removes the 'encoding' pragma. And improve mpdexec.pl to be a bit more flexible: command-line arguments will be correctly quoted for MPD, and also add a mode to accept commands on standard input which helps performance with long command sequences.
thumbnailer: Follow only one level of symbolic link. Since my music is all in git annex now, the thumbnailer follows the cover art symlinks all the way to the annex object directory. This is less than helpful, since the intention was to locate the album scan directory. Change the --image mode to just read the link once and then stop.
Don't lock the screen on a double scroll lock. A double scroll lock is used to communicate with my KVM. This should not have a side effect of locking the screen, so arrange for the screen to only lock if the scroll lock key is pressed once. Unfortunately, FVWM does not appear to have "single press" versus "double press" for key bindings (although it does for mouse bindings...), so we simulate it using a timer.