- _() is no more installed in __builtin__
- instead, there is a new sat.core.i18n module
- added D_() method for deferred translation
- languageSwitch method allow to dynamically change translation language
- import gettext is tested against ImportError, and dummy methods are used when not available (mainly useful for Libervia)
- private values are now stored in storage (currently sqlite database) and splitted in normal/binary storage. Normal storage is for string key/values, binary storage is for string key and any python data for value
- PersistentDict and PersistentBinaryDict are sugar classes to manage the data in storage thought a python dictionary like class.