Every time I upgrade SlimServer, I forget about my custom fonts (the excellent
ones provided by bobv @ http://mylefteye.com/sbgfonts).  I have to remember to
copy them from the old install to the new.  One of these days, I'll forget and
delete the old ones, then I'll be sorry.  It would be nice if there was a way to
avoid this problem (which probably also affects added plugins).

My suggestion is to allow the user to specify the path to a directory that
contains additional fonts.  Thus I could create ~slim/Graphics, and put my
custom fonts there, and not worry about breakage during an upgrade.