[messages] rename class to msg_class

makes it possible to use the python parser using xmlobject since class is a reserved word.

sw/lib/ocaml/pprz.ml

@@ -609,7 +609,8 @@ module MessagesOfXml(Class:CLASS_Xml) = struct
   let messages_by_id, messages_by_name =
     try
       let select = fun x -> Xml.attrib x "name" = Class.name in
-      parse_class (ExtXml.child Class.xml ~select "class")
+      let xml_class = try ExtXml.child Class.xml ~select "msg_class" with Not_found -> ExtXml.child Class.xml ~select "class" in
+      parse_class xml_class
     with
         Not_found -> failwith (sprintf "Unknown message class: %s" Class.name)
   let messages = messages_by_id

sw/lib/ocaml/ubx.ml

@@ -92,7 +92,7 @@ let ubx_xml =
 
 let ubx_get_class = fun name ->
   let ubx_xml = Lazy.force ubx_xml in
-  ExtXml.child ubx_xml ~select:(fun x -> ExtXml.attrib x "name" = name) "class"
+  ExtXml.child ubx_xml ~select:(fun x -> ExtXml.attrib x "name" = name) "msg_class"
 
 let ubx_get_msg = fun ubx_class name ->
   ExtXml.child ubx_class ~select:(fun x -> ExtXml.attrib x "name" = name) "message"

sw/lib/python/messages_xml_map.py

@@ -40,7 +40,7 @@ def GetOptions():
 def ParseMessages():
     from lxml import etree
     tree = etree.parse( messages_path)
-    for the_class in tree.xpath("//class[@name]"):
+    for the_class in tree.xpath("//msg_class[@name]"):
         class_name = the_class.attrib['name']
         if class_name not in message_dictionary:
             message_dictionary_id_name[class_name] = {}