bug#5687: 23.1; flyspell doublon at start of sentence

[Kevin Ryde]

M-x flyspell-buffer in a buffer containing

    Likewise likewise

doesn't highlight that as a doublon, where I hoped that it would, as is
does for say lower case "likewise likewise".

I struck this when I doubled-up at the start of a sentence.  Maybe some
programming abbreviation things ought to be case sensitive, but I think
a first letter capital like this should be insensitive.


In GNU Emacs 23.1.1 (i486-pc-linux-gnu, GTK+ Version 2.16.5)
 of 2009-09-14 on raven, modified by Debian
configured using `configure  '--build=i486-linux-gnu' '--host=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/emacs23:/etc/emacs:/usr/local/share/emacs/23.1/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.1/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.1/leim'
 '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 
'build_alias=i486-linux-gnu' 'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -g 
-O2' 'LDFLAGS=-g' 'CPPFLAGS=''

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