BTNPIN can now be disabled by setting to -1 (fixes #1237)

Added HEX color receiving to JSON API
Moved Kelvin color receiving in JSON API

wled00/fcn_declare.h

@@ -43,6 +43,7 @@ void colorXYtoRGB(float x, float y, byte* rgb); // only defined if huesync disab
 void colorRGBtoXY(byte* rgb, float* xy); // only defined if huesync disabled TODO
 
 void colorFromDecOrHexString(byte* rgb, char* in);
+bool colorFromHexString(byte* rgb, const char* in);
 void colorRGBtoRGBW(byte* rgb); //rgb to rgbw (http://codewelt.com/rgbw). (RGBW_MODE_LEGACY)
 
 //dmx.cpp