detect config is readonly, adalight and other stuff (#333)

* update lightberry sketches
update compilehowwto (windows disclaimer)
some refactoring in main cmakelists + preparation for windows compile
tune ada driver, set delayAfterConnect default to 1.5s because some arduino (e.g. mega r3) needs this
set priority min/max for grabber/network services - prevent colliding prios between webui/background stuff and grabbers/net services

* add check if config is writable. TODO do something usefull in webui

* fix indention error

* fix typo

* fix webui can't write led config

* typo

* fix cmakelists

* change methode of detecting linux

libsrc/leddevice/LedDeviceAdalight.h

@@ -31,6 +31,7 @@ private:
 	///
 	virtual int write(const std::vector<ColorRgb> & ledValues);
 	
+	const short _headerSize;
 	bool _ligthBerryAPA102Mode;
 };