[trigger] Refactorisation (voir détails) - On passe aux tests

* Pour une plus grande modularité, event a été refactorisé, ce qui
 a impliqué de réécrire le fonctionnement des services.
 * Maintenant, y a plus qu'à tester.

gestion/trigger/services/service.py

@@ -0,0 +1,38 @@
+#!/bin/bash /usr/scripts/python.sh
+# -*- coding: utf-8 -*-
+
+"""
+This module provides a basic service class to other services. It should *NOT*
+be referenced in configuration of trigger.
+"""
+
+class BasicService(object):
+    """Basic service handler. Other services should inherit fron this one.
+
+    """
+
+    changes_trigger = {}
+
+    @classmethod
+    def get_changes(cls, body, diff):
+        """Looks for changes and creates messages to send back
+
+        """
+        # list of all messages to send.
+        msg_list = []
+
+        # lists all functions to call
+        func_list = set()
+        for (attrib, functions) in cls.changes_trigger.iteritems():
+            if attrib in diff:
+                func_list.update(functions)
+        for function in func_list:
+            msg_list.append(function(body, diff))
+        return msg_list
+
+    @classmethod
+    def regen(cls, body):
+        """This method is referenced to avoid uncaught exceptions
+
+        """
+        pass