pre-merge

cleanup:
- version increase
- clean up debug messages
- minor fixes in platformio.ini
- fix compilation with -D WLED_DISABLE_2D

helping the compiler to optimize:
- a few more __attribute__((pure))
- fx.cpp marked a few local functions as "static"

platformio.ini

@@ -887,6 +887,7 @@ build_flags_S =
   -Wno-attributes -Wno-unused-variable -Wno-unused-function -Wno-deprecated-declarations ;disables some stupid warnings
   ;-D WLED_DISABLE_BROWNOUT_DET ; enable if you get "brownout detected" errors at startup 
   -D WLED_USE_MY_CONFIG
+  ; -D WLED_DISABLE_2D ;; un-comment to build a firmware without 2D matrix support
   ; -D WLED_USE_CIE_BRIGHTNESS_TABLE ;; experimental: use different color / brightness lookup table
   -D USERMOD_AUDIOREACTIVE
   -D UM_AUDIOREACTIVE_USE_NEW_FFT ; use latest (upstream) FFTLib, instead of older library modified by blazoncek. Slightly faster, more accurate, needs 2KB RAM extra   
@@ -1009,6 +1010,7 @@ build_flags = ${common.build_flags} ${esp32.build_flagsV4} ${common_mm.build_fla
   -Wno-misleading-indentation -Wno-format-truncation 
   -Wshadow=compatible-local ;; emit warning in case a local variable "shadows" another local one
   ;-Wstack-usage=2732       ;; warn if a function needs more that 30% of availeable stack ("stack usage might be unbounded", "stack usage is 2824 bytes")
+  ;-Wsuggest-attribute=const -Wsuggest-attribute=pure ;;  ask compiler for hints on attributes
   -D WLED_ENABLE_DMX_INPUT
 lib_deps = ${esp32.lib_depsV4} ${common_mm.lib_deps_S}
   https://github.com/someweisguy/esp_dmx.git#v3.0.2-beta  ;; for DMX_INPUT
@@ -1124,7 +1126,7 @@ build_unflags = ${common.build_unflags}
   -D CORE_DEBUG_LEVEL=0
 build_flags = ${esp32_4MB_M_base.build_flags} 
   ${Debug_Flags.build_flags}
-  -D WLED_DEBUG_HEAP ;; WLEDMM enable heap debugging
+  ; -D WLED_DEBUG_HEAP ;; WLEDMM enable heap debugging (needs newer framework versions)
   -D CORE_DEBUG_LEVEL=2   ;; 2=warning
   -D WLED_RELEASE_NAME=esp32_16MB_M_debug
 monitor_filters = esp32_exception_decoder