[1MB OTA] Add small build to allow for 1MB OTA

Using 128k SPIFFS and 2-step OTA image, it is possible to perform an OTA update on 1 MB nodes.
This 2-step image does not have the ArduinoOTA service running, but does allow for manual upload using web interface.
ArduinoOTA needs 8 kB more, which will not work at the moment.

platformio.ini

@@ -135,6 +135,10 @@ monitor_speed             = 115200
 platform                  = ${common.platform}
 build_flags               =
 
+[normal_ota]
+platform                  = ${common.platform}
+build_flags               = -DPLUGIN_BUILD_MINIMAL_OTA
+
 [testing]
 platform                  = ${core_2_4_2.platform}
 build_flags               = -DPLUGIN_BUILD_TESTING
@@ -154,6 +158,13 @@ board_upload.maximum_size = 786432
 build_unflags             = ${common.build_unflags}
 build_flags               = ${common.build_flags} -Wl,-Tesp8266.flash.1m128.ld
 
+[esp8266_1M_OTA]
+board_build.flash_mode    = dout
+board_build.f_cpu         = ${common.board_build.f_cpu}
+board_upload.maximum_size = 616448
+build_unflags             = ${common.build_unflags}
+build_flags               = ${common.build_flags} -Wl,-Tesp8266.flash.1m128.ld
+
 [esp8285_1M]
 board                     = esp8285
 board_upload.maximum_size = ${esp8266_1M.board_upload.maximum_size}
@@ -285,6 +296,23 @@ board_build.flash_mode    = ${esp8266_1M.board_build.flash_mode}
 build_unflags             = ${esp8266_1M.build_unflags}
 build_flags               = ${esp8266_1M.build_flags} ${normal.build_flags}
 
+[env:minimal_ESP8266_1024_OTA]
+platform                  = ${common.platform}
+lib_deps                  = ${common.lib_deps}
+lib_ignore                = ${common.lib_ignore}
+lib_ldf_mode              = ${common.lib_ldf_mode}
+lib_archive               = ${common.lib_archive}
+framework                 = ${common.framework}
+upload_speed              = ${common.upload_speed}
+monitor_speed             = ${common.monitor_speed}
+board                     = ${common.board}
+board_upload.maximum_size = ${esp8266_1M_OTA.board_upload.maximum_size}
+board_build.f_cpu         = ${esp8266_1M_OTA.board_build.f_cpu}
+board_build.flash_mode    = ${esp8266_1M_OTA.board_build.flash_mode}
+build_unflags             = ${esp8266_1M_OTA.build_unflags}
+build_flags               = ${esp8266_1M_OTA.build_flags} ${normal_ota.build_flags}
+
+
 [env:normal_core_241_ESP8266_1024]
 platform                  = ${core_2_4_1.platform}
 lib_deps                  = ${common.lib_deps}

src/ESPEasy-Globals.h

@@ -519,7 +519,7 @@ bool showSettingsFileLayout = false;
   #ifdef FEATURE_MDNS
     #include <ESP8266mDNS.h>
   #endif
-  #define SMALLEST_OTA_IMAGE 272*1024 // smallest known 2-step OTA image
+  #define SMALLEST_OTA_IMAGE 276848 // smallest known 2-step OTA image
   #define MAX_SKETCH_SIZE 1044464
   #ifdef FEATURE_ARDUINO_OTA
     #include <ArduinoOTA.h>

src/define_plugin_sets.h

@@ -44,7 +44,6 @@ To create/register a plugin, you have to :
     #define PLUGIN_BUILD_IR
 #endif
 
-
 #ifdef PLUGIN_BUILD_DEV
     #define  PLUGIN_SET_EXPERIMENTAL
     #define  CONTROLLER_SET_EXPERIMENTAL
@@ -71,6 +70,46 @@ To create/register a plugin, you have to :
     #define  NOTIFIER_SET_STABLE
 #endif
 
+#ifdef PLUGIN_BUILD_MINIMAL_OTA
+    #define PLUGIN_DESCR  "Minimal 1M OTA"
+
+    #define CONTROLLER_SET_NONE
+
+    #define USES_C001   // Domoticz HTTP
+    #define USES_C002   // Domoticz MQTT
+    #define USES_C005   // OpenHAB MQTT
+//    #define USES_C006   // PiDome MQTT
+    #define USES_C008   // Generic HTTP
+    #define USES_C009   // FHEM HTTP
+//    #define USES_C010   // Generic UDP
+    #define USES_C013   // ESPEasy P2P network
+
+    #define NOTIFIER_SET_STABLE
+    #define PLUGIN_SET_NONE
+
+    #ifndef USES_P001
+        #define USES_P001   // switch
+    #endif
+    #ifndef USES_P026
+      #define USES_P026   // SysInfo
+    #endif
+    #ifndef USES_P033
+      #define USES_P033   // Dummy
+    #endif
+    #ifndef USES_P037
+//        #define USES_P037   // MQTTImport
+    #endif
+
+    #ifndef USES_P004
+//        #define USES_P004   // Dallas
+    #endif
+    #ifndef USES_P005
+//        #define USES_P005   // DHT
+    #endif
+
+#endif
+
+
 
 /******************************************************************************\
  * IR plugins *****************************************************************
@@ -333,9 +372,6 @@ To create/register a plugin, you have to :
     #ifndef USES_P028
         #define USES_P028   // BME280
     #endif
-    #ifndef USES_P030
-        #define USES_P030   // BMP280
-    #endif
 #endif
 
 #ifdef PLUGIN_SET_ONLY_LEDSTRIP