* no longer track "current" simulator, as this resulted in too many signals
* CCentralMultiSimulatorModelCachesProvider keeping all model caches "in one memory location"
* style changes
* loader/multi cache can clear caches if that is ever needed
* check if cache needs to be synchronized when loaded and if, do it
* emit changed signal if caches are set
* simulator info for FS family / as set
* fixed synchronized typo
* info string for caches
* getter for cached models from the loaders
* get all FS family models (FSX/P3D/FS9) from list
* call of non-virtual function in ctor
* use getCopy
* return number of merged models
* change current simulator in model set loader (fixes infinite loop: change data -> signal -> change data).
* adjustments to use deferred caches
* removed simulator from CAircraftModelSetLoader`s signature as it was not used
* only change current simulator when explicitly set (avoid unintended setting)
* added function to obtain number of elements from model caches
* removed from component cache
* kept renamed component caches as stubs for later usage
refs #646, removed gui state cache as it causes build issues on Jenkins
(idea was to keep the classes as stubs for later usage)
* moved caches to blackmisc
* used CModelCaches in loader
* applied changes in simulator specific loader classes
* renamed find function to findFirstByModelStringOrDefault
* made merge function static so it can be used elsewhere
