bug#12639: 24.1; woman.el points vs pica scaling

[Kevin Ryde]

The file picapoints.1 viewed with

    M-x woman-find-file picapoints.1

gives

    12 point spacing                      xxx
    12 picas spacing                      xxx

where I expected that "12p" points would be much less than "12P" picas,
something like maybe

     12 point spacing    xxx
     12 picas spacing                      xxx

It looks like case-fold-search is true in woman-parse-numeric-value
causing "p" points and "P" picas not to be distinguished.

I can't tell if that's meant to be so.  There seems to be duelling
`let's of case significance.  Ensuring it where it matters per diff
below might be a good idea.

2012-10-14  Kevin Ryde  <user42@zip.com.au>

        * woman.el (woman-parse-numeric-value): case-fold-search nil to ensure
        "p" points and "P" picas scaling are distinguished as intended.


I struck this on output from recent perl pod2man where there's some
spacing to make "C++" look good, per cplusplus.1 below.  It's meant for
troff, but when woman wrongly takes it as 1 pica instead of 1 point the
movement forward and back doesn't add up and a space after the construct
is lost, so giving

    Blah C^++blah.

With case-significance fixed it becomes the intended

    Blah C^++ blah.

picapoints.1
Description: Text document

woman.el.picas.diff
Description: Text Data

cplusplus.1
Description: Text document

In GNU Emacs 24.1.1 (i486-pc-linux-gnu, GTK+ Version 2.24.8)
 of 2012-08-07 on blah.blah, modified by Debian
Configured using:
 `configure '--build' 'i486-linux-gnu' '--build' 'i486-linux-gnu'
 '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib'
 '--localstatedir=/var/lib' '--infodir=/usr/share/info'
 '--mandir=/usr/share/man' '--with-pop=yes'
 
'--enable-locallisppath=/etc/emacs24:/etc/emacs:/usr/local/share/emacs/24.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.1/site-lisp:/usr/share/emacs/site-lisp'
 '--with-crt-dir=/usr/lib/i386-linux-gnu' '--with-x=yes'
 '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars'
 'build_alias=i486-linux-gnu' 'CFLAGS=-g -O2 -fstack-protector
 --param=ssp-buffer-size=4 -Wformat -Werror=format-security -Wall'
 'CPPFLAGS=-D_FORTIFY_SOURCE=2''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_AU
  value of $XMODIFIERS: nil
  locale-coding-system: iso-latin-1-unix
  default enable-multibyte-characters: t