Moved begin above init, reset historic buffer sizes

src/TinyGsmClientSIM800.h

@@ -13,6 +13,10 @@
 //#define TINY_GSM_DEBUG Serial
 //#define TINY_GSM_USE_HEX
 
+#if !defined(TINY_GSM_RX_BUFFER)
+  #define TINY_GSM_RX_BUFFER 64
+#endif
+
 #define TINY_GSM_MUX_COUNT 5
 
 #include <TinyGsmCommon.h>
@@ -162,6 +166,10 @@ public:
    * Basic functions
    */
 
+  bool begin(const char* pin = NULL) {
+    return init(pin);
+  }
+
   bool init(const char* pin = NULL) {
     DBG(GF("### TinyGSM Version:"), TINYGSM_VERSION);
     if (!testAT()) {
@@ -178,10 +186,6 @@ public:
     return true;
   }
 
-  bool begin(const char* pin = NULL) {
-    return init(pin);
-  }
-
   String getModemName() {
     #if defined(TINY_GSM_MODEM_SIM800)
       return "SIMCom SIM800";
@@ -339,6 +343,7 @@ TINY_GSM_MODEM_WAIT_FOR_NETWORK()
   /*
    * GPRS functions
    */
+
   bool gprsConnect(const char* apn, const char* user = NULL, const char* pwd = NULL) {
     gprsDisconnect();
 
@@ -621,6 +626,7 @@ TINY_GSM_MODEM_WAIT_FOR_NETWORK()
   /*
    * Time functions
    */
+
   String getGSMDateTime(TinyGSMDateTimeFormat format) {
     sendAT(GF("+CCLK?"));
     if (waitResponse(2000L, GF(GSM_NL "+CCLK: \"")) != 1) {