Include new branch of IRremoteESP8266 to save 21k (#582)

This saves 21024 bytes of program space

platformio.ini

@@ -27,6 +27,18 @@ build_flags =
   -w ; supresses all C/C++ warnings
   ; -D VERSION=0.8.5
   ; -D DEBUG
+  #build_flags for the IRremoteESP8266 library (enabled decoders have to appear here)
+  -D _IR_ENABLE_DEFAULT_=false 
+  -D DECODE_HASH=true 
+  -D DECODE_NEC=true 
+  -D DECODE_SONY=true 
+  -D DECODE_PANASONIC=true 
+  -D DECODE_JVC=true 
+  -D DECODE_SAMSUNG=true
+  -D DECODE_LG=true
+  -D DECODE_SANYO=true
+  -D DECODE_SHARP=true 
+  -D DECODE_DENON=true 
 # TODO replace libs in /lib with managed libs in here if possible.
 # If they are not changed it's just a matter of setting the correct version and change the import statement
 lib_deps_external =
@@ -39,7 +51,9 @@ lib_deps_external =
   AsyncTCP@1.0.3
   Esp Async WebServer@1.2.0
   #ArduinoJson@5.13.5
-  IRremoteESP8266@2.7.2
+  #IRremoteESP8266@2.7.2
+  #For saving 20k program space the brnach "compile_flags" will be used:
+  https://github.com/crankyoldgit/IRremoteESP8266.git#compile_flags
   #Time@1.5
   #Timezone@1.2.1
   #For use SSD1306 0.91" OLED display uncomment following