add export method to value in api

tiramisu/__init__.py

@@ -22,7 +22,7 @@ from .setting import owners, undefined
 
 allfuncs = ['MetaConfig',
             'GroupConfig',
-            'Config'
+            'Config',
             'getapi',
             'APIError',
             'undefined']

tiramisu/api.py

@@ -651,6 +651,9 @@ class TiramisuContextValue(TiramisuContext):
               path):
         self.config_bag.config.reset(path, self.config_bag)
 
+    def export(self):
+        return self.config_bag.config.cfgimpl_get_values()._p_.exportation()
+
 
 class TiramisuContextOwner(TiramisuContext):
     @count