yaml: Represent weboob date[time] objects as timestamps

Unfortunately, I couldn't make timestamps always load
as our date[time] objects, at least with CLoader.

weboob/tools/config/yamlconfig.py

@@ -18,11 +18,15 @@
 # along with weboob. If not, see <http://www.gnu.org/licenses/>.
 
 
+import logging
 import os
 import tempfile
-import logging
+
+import weboob.tools.date
 import yaml
 
+from .iconfig import ConfigError, IConfig
+
 try:
     from yaml import CLoader as Loader
     from yaml import CDumper as Dumper
@@ -30,12 +34,22 @@ except ImportError:
     from yaml import Loader
     from yaml import Dumper
 
-from .iconfig import IConfig, ConfigError
 
 
 __all__ = ['YamlConfig']
 
 
+class WeboobDumper(Dumper):
+    pass
+
+
+WeboobDumper.add_representer(weboob.tools.date.date,
+                             WeboobDumper.represent_date)
+
+WeboobDumper.add_representer(weboob.tools.date.datetime,
+                             WeboobDumper.represent_datetime)
+
+
 class YamlConfig(IConfig):
     def __init__(self, path):
         self.path = path
@@ -59,7 +73,7 @@ class YamlConfig(IConfig):
     def save(self):
         # write in a temporary file to avoid corruption problems
         with tempfile.NamedTemporaryFile(dir=os.path.dirname(self.path), delete=False) as f:
-            yaml.dump(self.values, f, Dumper=Dumper)
+            yaml.dump(self.values, f, Dumper=WeboobDumper)
         os.rename(f.name, self.path)
 
     def get(self, *args, **kwargs):