fix warning (#161)

* fix warning
comparison of int and unsigned int
* convert tabs to spaces
to remove warnings -Wmisleading-indentation

Author: vondraussen

src/Modbus.cpp

@@ -123,9 +123,9 @@ bool Modbus::removeReg(TAddress address, uint16_t numregs) {
 bool Modbus::addReg(TAddress address, uint16_t* value, uint16_t numregs) {
     if (0xFFFF - address.address < numregs)
         numregs = 0xFFFF - address.address;
-	for (uint16_t k = 0; k < numregs; k++)
-		addReg(address + k, value[k]);
-	return true;
+    for (uint16_t k = 0; k < numregs; k++)
+        addReg(address + k, value[k]);
+    return true;
 }
 
 void Modbus::slavePDU(uint8_t* frame) {

src/ModbusRTU.cpp

@@ -82,8 +82,8 @@ bool ModbusRTUTemplate::rawSend(uint8_t slaveId, uint8_t* frame, uint8_t len) {
     _port->flush();
     if (_txPin >= 0)
         digitalWrite(_txPin, _direct?LOW:HIGH);
-	//delay(_t);
-	return true;
+    //delay(_t);
+    return true;
 }
 
 uint16_t ModbusRTUTemplate::send(uint8_t slaveId, TAddress startreg, cbTransaction cb, uint8_t unit, uint8_t* data, bool waitResponse) {

src/ModbusTCPTemplate.h

@@ -232,7 +232,7 @@ void ModbusTCPTemplate<SERVER, CLIENT>::task() {
 	for (n = 0; n < MODBUSIP_MAX_CLIENTS; n++) {
 		if (!tcpclient[n]) continue;
 		if (!tcpclient[n]->connected()) continue;
-		while (millis() - taskStart < MODBUSIP_MAX_READMS &&  tcpclient[n]->available() > sizeof(_MBAP)) {
+		while (millis() - taskStart < MODBUSIP_MAX_READMS &&  (size_t)tcpclient[n]->available() > sizeof(_MBAP)) {
 			tcpclient[n]->readBytes(_MBAP.raw, sizeof(_MBAP.raw));	// Get MBAP
 
 			if (__swap_16(_MBAP.protocolId) != 0) {   // Check if MODBUSIP packet. __swap is usless there.