new brightness handling (#430)

* clean color adjustment

* now a prio duration of "0" means infinity

* implement dynamic 'just in time' initialization

* implement new brightness handling

* cahnge access level

* i18n fix

* - cleanup brightness stuff
- update webserver, now with initial ssl support

* - backlightThreshold is now 0-100 instead 0-1
- better performance for brightness - use piecewise linear instead of sqrt

config/hyperion.config.json.default

@@ -38,9 +38,10 @@
 				"gammaRed"   : 1.5,
 				"gammaGreen" : 1.5,
 				"gammaBlue"  : 1.5,
-				"backlightThreshold"  : 0.0,
+				"backlightThreshold"  : 0,
 				"backlightColored"  : false,
-				"brightness" : 0.75
+				"brightness" : 100,
+				"brightnessCompensation" : 100
 			}
 		]
 	},