Added optional homeSpan.setTimeServer() method

If specified, HomeSpan will try to get internet time after establishing WiFi connection.  Consumes one socket connection.

src/HomeSpan.cpp

@@ -559,6 +559,15 @@ void Span::checkConnect(){
     }
   }
 
+  if(timeServer){
+    Serial.printf("Acquiring Time from %s... ",timeServer,timeZone);
+    configTzTime(timeZone,timeServer);
+    getLocalTime(&timeinfo);
+    char c[65];
+    strftime(c,64,"%a %b %e %Y %I:%M:%S %p",&timeinfo);
+    Serial.printf("%s (%s)\n\n",c,timeZone);
+  }
+  
   Serial.printf("Starting HAP Server on port %d supporting %d simultaneous HomeKit Controller Connections...\n",tcpPortNum,maxConnections);
 
   hapServer->begin();

src/HomeSpan.h

@@ -113,6 +113,9 @@ struct Span{
   nvs_handle charNVS;                           // handle for non-volatile-storage of Characteristics data
   nvs_handle wifiNVS=0;                         // handle for non-volatile-storage of WiFi data
   char pairingCodeCommand[12]="";               // user-specified Pairing Code - only needed if Pairing Setup Code is specified in sketch using setPairingCode()
+  const char *timeZone=NULL;                    // optional time-zone specification
+  const char *timeServer=NULL;                  // optional time server to use for acquiring clock time
+  struct tm timeinfo;                           // optional time info structure
   
   boolean connected=false;                      // WiFi connection status
   unsigned long waitTime=60000;                 // time to wait (in milliseconds) between WiFi connection attempts
@@ -192,7 +195,6 @@ struct Span{
   void setWifiCallback(void (*f)()){wifiCallback=f;}                      // sets an optional user-defined function to call once WiFi connectivity is established
   void setPairCallback(void (*f)(boolean isPaired)){pairCallback=f;}      // sets an optional user-defined function to call when Pairing is established (true) or lost (false)
   void setApFunction(void (*f)()){apFunction=f;}                          // sets an optional user-defined function to call when activating the WiFi Access Point  
-
   void enableAutoStartAP(){autoStartAPEnabled=true;}                      // enables auto start-up of Access Point when WiFi Credentials not found
   void setWifiCredentials(const char *ssid, const char *pwd);             // sets WiFi Credentials
 
@@ -200,6 +202,7 @@ struct Span{
   void deleteStoredValues(){processSerialCommand("V");}                         // deletes stored Characteristic values from NVS  
 
   void enableOTA(boolean auth=true){otaEnabled=true;otaAuth=auth;reserveSocketConnections(1);}                        // enables Over-the-Air updates, with (auth=true) or without (auth=false) authorization password  
+  void setTimeServer(const char *serv, const char *tz){timeServer=serv;timeZone=tz;reserveSocketConnections(1);}      // sets optional time server and time zone
   
   [[deprecated("Please use reserveSocketConnections(n) method instead.")]]
   void setMaxConnections(uint8_t n){requestedMaxCon=n;}                   // sets maximum number of simultaneous HAP connections