Multi-update

- 0.15.0-b2
- WS2805 support (NeoPixelBus 2.7.9)
- generic PSRAM support (ESP32 rev.1 still needs compile fix)
- BREAKING: default LEDPIN 2 (due to PSRAM)
- PinManager optimisations

platformio_override.sample.ini

@@ -155,9 +155,8 @@ build_flags = ${common.build_flags_esp8266}
 ; set default color order of your led strip
 ;   -D DEFAULT_LED_COLOR_ORDER=COL_ORDER_GRB
 ;
-; use PSRAM if a device (ESP) has one
-;   -DBOARD_HAS_PSRAM
-;   -D WLED_USE_PSRAM
+; use PSRAM on classic ESP32 rev.1 (rev.3 or above has no issues)
+;   -DBOARD_HAS_PSRAM -mfix-esp32-psram-cache-issue
 ;
 ; configure I2C and SPI interface (for various hardware)
 ;   -D I2CSDAPIN=33 # initialise interface