Remove dead symbolic links

for i in `find .`; do if (test -h $i); then file $i|grep broken; fi; done

./es/99book.bib: broken symbolic link to `../en/99book.bib'
./es/bookhtml.cfg: broken symbolic link to `../en/bookhtml.cfg'
./es/fixhtml.py: broken symbolic link to `../en/fixhtml.py'
./es/hgbook.css: broken symbolic link to `../en/hgbook.css'
./es/htlatex.book: broken symbolic link to `../en/htlatex.book'

     1.1 --- a/en/examples/mq.dodiff	Wed May 30 22:02:48 2007 -0700
     1.2 +++ b/en/examples/mq.dodiff	Thu May 21 14:26:31 2009 +0800
     1.3 @@ -2,8 +2,8 @@
     1.4  
     1.5  #$ name: diff
     1.6  
     1.7 -echo 'this is my first line' > oldfile
     1.8 -echo 'my first line is here' > newfile
     1.9 +echo 'this is my original thought' > oldfile
    1.10 +echo 'i have changed my mind' > newfile
    1.11  
    1.12  diff -u oldfile newfile > tiny.patch
    1.13