<nitpicking>

"root.h"
line 67: static int toLower(dchar c) { return isUpper(c) ? towlower(c) : c; }

why two library calls here instead of just one?  (isUpper becomes iswupper)  am
I missing something?  towlower() should leave arg unchanged if already
lowercase.

// my suggestion
static int toLower(dchar c) { towlower(c); }

<crazy suggestion>
in the vein of http://kx.com/a/k/connect/c/k20.h

// try this, it does take some getting used to, but one gets increased code density.

"dchar.h"
typedef wchar_t W;