User configurable usermods.

- Utilizing addToConfig() & readFromConfig()
- UM configuration Settings page
- MQTT support for usermods
- A few sample usermods including rewritten Temparature and new Multi-Relay

wled00/fcn_declare.h

@@ -150,6 +150,7 @@ void _overlayCronixie();
 void _drawOverlayCronixie();
 
 //playlist.cpp
+void shufflePlaylist();
 void unloadPlaylist();
 void loadPlaylist(JsonObject playlistObject);
 void handlePlaylist();
@@ -186,10 +187,12 @@ class Usermod {
     virtual void readFromJsonState(JsonObject& obj) {}
     virtual void addToConfig(JsonObject& obj) {}
     virtual void readFromConfig(JsonObject& obj) {}
+    virtual void onMqttConnect(bool sessionPresent) {}
+    virtual bool onMqttMessage(char* topic, char* payload) { return false; }
     virtual uint16_t getId() {return USERMOD_ID_UNSPECIFIED;}
 };
 
-class UsermodManager {
+class UsermodManager : public Usermod {
   private:
     Usermod* ums[WLED_MAX_USERMODS];
     byte numMods = 0;
@@ -206,7 +209,8 @@ class UsermodManager {
 
     void addToConfig(JsonObject& obj);
     void readFromConfig(JsonObject& obj);
-
+    void onMqttConnect(bool sessionPresent);
+    bool onMqttMessage(char* topic, char* payload);
     bool add(Usermod* um);
     Usermod* lookup(uint16_t mod_id);
     byte getModCount();