Began implementing key-value store support.

Serializing help documentation requires such support, which transitively
requires a host of other dependencies I hadn't previously considered --
in particular, hexadecimal encoding filesystem-reserved characters in
key filenames.

"Such is the warp and weft of the heft we lift, mightily/
 Engorged and fat dripping on
 What's left of timely Sun-ripped left-overs."