Rational: Normally calling synchronize multiple times does not matter. However, it can time out if the cache is in use (e.g. saving) and create an exception. This exception is just unwanted "noise".
* multi format compatible (automatically detect format)
* flag if cache values shall be overridden
* init from resource files (those are the files coming with the installer)
* automatically read in background if reader is (already) in its own thread (otherwise cache.set() ASSERT)
* in case the internet provider is down, this is not detected
* extended test to detect if access is possible
* in case of downtime this indicated in status component
* use doWorkCheck
* relaxed doWorkCheck in unit tests
* removed isShuttingDown, gracefulShutdown
* set timer object name (in case something is wrong, we might see the name in the log)
* new read state "skipped"
* renamed to "isNetworkConnectedAndAccessible"
* checking before reading, which would only fail if network is not accessible
* added amit functions in readers
* cacheHasChanged functions (needed because data of caches are loaded in background)
* pinned small caches
* CDatabaseReader::readInBackgroundThread uses admitCaches now
* Ignore mode, not all applications need to load everything (mapping tool no airports)
* removed signal in airport reader which is already in base class
* added "virtual" keyword
* fixed another syncronize typo
* added allDbEntiiesUsed() to also reflect the config (ignore flag)
* ensure allSwiftDbData are signaled correctly even with ignore flag
* removed workaround in web data services
* removed convertFromDatabaseJson functions, not needed
* changed to use the correct static fromDatabaseJson functions
* fixed prefixes
* load correct Country object by loading it as nested object
* key and timestamp was missing in CAirport tuple metadata
