Added wifi fxns as shells where unsupported

Allows more flexibility downstream

src/TinyGsmClientA6.h

@@ -408,6 +408,8 @@ public:
   /*
    * WiFi functions
    */
+  bool networkConnect(const char* ssid, const char* pwd) TINY_GSM_ATTR_NOT_AVAILABLE;
+  bool networkDisconnect() TINY_GSM_ATTR_NOT_AVAILABLE;
 
   /*
    * GPRS functions
@@ -415,9 +417,8 @@ public:
   bool gprsConnect(const char* apn, const char* user = NULL, const char* pwd = NULL) {
     gprsDisconnect();
 
-    sendAT(GF("+CGATT=1"));
-    if (waitResponse(60000L) != 1)
-      return false;
+    sendAT(GF("EE"), 2);  // Set security to WPA2
+    if (waitResponse() != 1) goto fail;
 
     // TODO: wait AT+CGATT?
 

src/TinyGsmClientBG96.h

@@ -441,6 +441,8 @@ public:
   /*
    * WiFi functions
    */
+  bool networkConnect(const char* ssid, const char* pwd) TINY_GSM_ATTR_NOT_AVAILABLE;
+  bool networkDisconnect() TINY_GSM_ATTR_NOT_AVAILABLE;
 
   /*
    * GPRS functions

src/TinyGsmClientESP8266.h

@@ -408,6 +408,8 @@ public:
   /*
    * GPRS functions
    */
+  bool gprsConnect(const char* apn, const char* user = NULL, const char* pwd = NULL) TINY_GSM_ATTR_NOT_AVAILABLE;
+  bool gprsDisconnect() TINY_GSM_ATTR_NOT_AVAILABLE;
 
   /*
    * Messaging functions

src/TinyGsmClientM590.h

@@ -417,6 +417,8 @@ public:
   /*
    * WiFi functions
    */
+  bool networkConnect(const char* ssid, const char* pwd) TINY_GSM_ATTR_NOT_AVAILABLE;
+  bool networkDisconnect() TINY_GSM_ATTR_NOT_AVAILABLE;
 
   /*
    * GPRS functions

src/TinyGsmClientSIM800.h

@@ -462,6 +462,12 @@ public:
     return false;
   }
 
+  /*
+   * WiFi functions
+   */
+  bool networkConnect(const char* ssid, const char* pwd) TINY_GSM_ATTR_NOT_AVAILABLE;
+  bool networkDisconnect() TINY_GSM_ATTR_NOT_AVAILABLE;
+
   /*
    * GPRS functions
    */

src/TinyGsmClientUBLOX.h

@@ -440,6 +440,8 @@ public:
   /*
    * WiFi functions
    */
+  bool networkConnect(const char* ssid, const char* pwd) TINY_GSM_ATTR_NOT_AVAILABLE;
+  bool networkDisconnect() TINY_GSM_ATTR_NOT_AVAILABLE;
 
   /*
    * GPRS functions