Pull up latest mdoc(7) changes:

: 2004-05-10 Werner LEMBERG <wl@gnu.org>
:
: * tmac/doc-syms (doc-str-Lb-libposix, doc-str-Lb-libpthread,
: doc-str-Lb-librt): Reset font.
: (Lb): Rename doc-str-Lb' to doc-str-Lb1'.
: Provide `doc-str-Lb' to reset font.
: * tmac/groff_mdoc.man: Updated.

: 2004-07-08 Thomas Klausner <wiz@netbsd.org>
:
: * tmac/doc-syms (doc-str-St--p1003.1-2004): New string.
: * tmac/groff_mdoc.man: Updated.