Modification of emacs output: Pp.warning and al now output warning between special characters.  
Modification of emacs output: Pp.warning and al now output warning
between special characters.  

I had to add a hidden variable print_emacs and a function to set it to
true in Pp because using Options.print_emacs would have introduce a
circularity.
 

git-svn-id: a49b465eaba45b67e2e1e4e0b2c256a71f59fecb@8747 85f007b7-540e-0410-9357-904b9bb8a0f7

SamB/coq