A6 A7 gateway (GSM GPRS) (#195)

* init 2G gateway with SMS sending and receiving

* A6lib add

* add 2Ggateway call from setup and loop

* add schematic and image

config_2G.h

@@ -0,0 +1,46 @@
+/*  
+  OpenMQTTGateway  - ESP8266 or Arduino program for home automation 
+
+   Act as a wifi or ethernet gateway between your 433mhz/infrared IR signal  and a MQTT broker 
+   Send and receiving command by MQTT
+ 
+  This gateway enables to set your parameters for the 2G gateway
+
+    Copyright: (c)Florian ROBERT
+  
+    This file is part of OpenMQTTGateway.
+    
+    OpenMQTTGateway is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    OpenMQTTGateway is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*-------------------2G topics & parameters----------------------*/
+//433Mhz MQTT Subjects and keys
+#define subjectMQTTto2G  Base_Topic Gateway_Name "/commands/MQTTto2G"
+#define subject2GtoMQTT  Base_Topic Gateway_Name "/2GtoMQTT"
+#define subjectGTW2GtoMQTT  Base_Topic Gateway_Name "/2GtoMQTT"
+#define subject2GtoMQTTphone  Base_Topic Gateway_Name "/2GtoMQTT/phone"
+#define subject2GtoMQTTdate  Base_Topic Gateway_Name "/2GtoMQTT/date"
+#define subject2GtoMQTTmessage  Base_Topic Gateway_Name "/2GtoMQTT/message"
+#define _2GPhoneKey "PHO_" // phone number define the phone number to send the SMS MQTT->2G
+
+#define _2G_MODULE_BAUDRATE 9600
+#define _2G_MIN_SIGNAL 30
+#define _2G_MAX_SIGNAL 1000
+
+/*-------------------PIN DEFINITIONS----------------------*/
+#define _2G_TX_PIN D6 //D6 to A6 RX, 
+#define _2G_RX_PIN D7 //D7 to A6 TX
+#define _2G_PWR_PIN D5
+#define _2G_RST_PIN D0
+