- Replaced a self. by cls. in leobject
- Changed default value for runtest option

- Changed the way of instanciating results object in get (using __new__ )

- now we have a LodelHook to trigger migration handlers loading
- datasources initialization in dyncode is now trigger by a hook (lodel2_plugin_loaded)
- datasources loading by dyncode is better

- The LeUpdateQuery implementation is broken or at least have huge performance issue
- Moved LeObject exceptions and LeQuery exceptions in lodel.leapi.exceptions

Adding a field to all non abstract classes to store in DB the name of corresponding LeObject subclass

- Now delete & update methods use filters & rel_filters

- deleting most of **datas to replace it with a standart dict argument
- using filters in childs of LeFilteredQuery