Big update: lots of little fixes and big speed boost on fire animation

-fixed fire burning more on the left side
-fixed crash in particle attractor
-added many improvements for ESP8266
-improved particle rendering efficiency
-efficiency improvements in general
-changed the way fire is rendered, now more than 2x faster
-re-tuned fire to new rendering, also seperately tuned it for ESP8266
-changed all random8() to random16() as it runs faster on ESPs
-some reformating
-some renaming of effect stuff
-fine tuning on falling particle effect
-improvements to collision handling (faster and better)
-added a (temporary) function for speed tests, will be removed again