Weak reference to Table, and helper method for setInfoFromDict.

With this helper, this ugly block of code:    

    template.cId = ([[params objectForKey:TEMPLATE_ID] isKindOfClass:[NSNull class]] || [params objectForKey:TEMPLATE_ID] == nil) ? template.cId : [[params objectForKey:TEMPLATE_ID]);

Becomes this:

    venue.cId = [self setObject:venue.cId toParam:[params objectForKey:VENUE_ID]];