refs #649, skip reading of info objects if only caches are used and emit signals when syncronized from cache

(applied after 1st performance fix for cache was ready)
* utility functions to detect if only caches are used
* renamed some functions
* renamed some db flags and added new ones

src/blackcore/db/icaodatareader.h

@@ -114,10 +114,6 @@ namespace BlackCore
             //! Write to static DB data file
             bool writeToJsonFiles(const QString &dir) const;
 
-        signals:
-            //! Combined read signal
-            void dataRead(BlackMisc::Network::CEntityFlags::Entity entity, BlackMisc::Network::CEntityFlags::ReadState state, int number);
-
         protected:
             //! \name cache handling for base class
             //! @{