xml parser : use @. instead of @\n otherwise the message

appears only if it is big enough (that give a strange behaviour ;) )

use debug flag

src/session/xml.mll

@@ -52,6 +52,8 @@
   exception Parse_error of string
 
   let parse_error s = raise (Parse_error s)
+  open Debug
+  let debug = register_flag "xml"
 
 }
 
@@ -73,7 +75,7 @@ rule xml_prolog = parse
 | "<?xml" space+ "version=\"1.0\"" space+ "encoding=\"UTF-8\"" space+ "?>"
     { xml_doctype "1.0" "" lexbuf }
 | "<?xml" ([^'?']|'?'[^'>'])* "?>"
-    { Format.eprintf "[Xml warning] prolog ignored@\n";
+    { dprintf debug "[Xml warning] prolog ignored@.";
       xml_doctype "1.0" "" lexbuf }
 | _
     { parse_error "wrong prolog" }
@@ -103,14 +105,14 @@ and elements group_stack element_stack = parse
   | "</" (ident as celem) space* '>'
       { match group_stack with
          | [] ->
-             Format.eprintf
-               "[Xml warning] unexpected closing Xml element `%s'@\n"
+             dprintf debug
+               "[Xml warning] unexpected closing Xml element `%s'@."
                celem;
              elements group_stack element_stack lexbuf
          | (elem,att,stack)::g ->
              if celem <> elem then
-               Format.eprintf
-                 "[Xml warning] Xml element `%s' closed by `%s'@\n"
+               dprintf debug
+                 "[Xml warning] Xml element `%s' closed by `%s'@."
                  elem celem;
              let e = {
                 name = elem;
@@ -120,13 +122,13 @@ and elements group_stack element_stack = parse
              in elements g (e::stack) lexbuf
        }
   | '<'
-      { Format.eprintf "[Xml warning] unexpected '<'@\n";
+      { dprintf debug "[Xml warning] unexpected '<'@.";
         elements group_stack element_stack lexbuf }
   | eof
       { match group_stack with
          | [] -> element_stack
          | (elem,_,_)::_ ->
-             Format.eprintf "[Xml warning] unclosed Xml element `%s'@\n" elem;
+             dprintf debug "[Xml warning] unclosed Xml element `%s'@." elem;
              pop_all group_stack element_stack
       }
   | _ as c