Modify mkterms
Close the anchor tag for letters.  Add Log line.
Modify Pages/bitsDemarcate.m4
Add Log and end-of-Source lines. Move include of bits Fix Defn to the
only page that needs it, terms.intro.me, instead of including it here.
Modify Pages/terms.intro.m4
Put the need-help anchor by itself, instead of wrapping it around the
include, in order to remove nested anchors.  Also include bits Fix
Defn here explicitly, rather than doing it through bits Demarcate.
Modify Pages/termsImpl.intro.m4
Remove second include of bits Fix Defn.  Put first include on its own line.
Modify Pages/twolevelExplain.html.m4
Include bits Fix Defn, to explain how to make suggestions, explicitly
here, instead of implicitly through bits Demarcate.
Modify Pages/bitsFixDefn.m4
Add Log and end-of-source lines.  (I was making other changes, but
they turned out to not be necessary.)