Adding default date for date_create and date_update columns

The dates are set in EmComponent::create() for date_create and in EmComponent::save() for date_update
The values are sets to datetime.datetime.utcnow() so we now that EVERY date in the db are in UTC, no matter django, database or even server configurations.
We will have to take care to convert dates from database to django timezone in dates fieldtypes.

Database/sqlsetup.py

@@ -5,8 +5,8 @@ import sqlalchemy as sql
 
 class SQLSetup(object): 
 
-    def initDb(self, dbconfname = 'default'):
-        db = SqlWrapper(read_db = dbconfname, write_db = dbconfname, alchemy_logs=True)
+    def initDb(self, dbconfname = 'default', alchemy_logs=None):
+        db = SqlWrapper(read_db = dbconfname, write_db = dbconfname, alchemy_logs=alchemy_logs)
         tables = self.get_schema()
         db.dropAll()
         db.createAllFromConf(tables)