Using Redactor as new WYSIWYG editor
Huge refactoring for blog product

* lint for models.py
* every function for the access in cache is now chunked
* [dbmodel] Programmi does not need Blog anymore
* [dbmodel] Blog's related programmi's now is a foreign key to Programmi

from now on we use [dbmodel] to identify changes to the db. They will be
useful when we'll migrate from appengine to vanilla.
italian to english

* [dbmodel] startgiorno is now start_day
* [dbmodel] endgiorno is now end_day
* [dbmodel] startora is now start_hour
* [dbmodel] endgiorno is now end_day