Change printf to cout in RPi examples

- For some reason, calling printf before cout results in a hang when
using SPIDEV with RPi
- Add fix for spidev per @mtiutiu #146 & #138

examples_RPi/gettingstarted.cpp

@@ -88,7 +88,7 @@ int main(int argc, char** argv){
   bool role_ping_out = true, role_pong_back = false;
   bool role = role_pong_back;
 
-  printf("RF24/examples/GettingStarted/\n");
+  cout << "RF24/examples/GettingStarted/\n";
 
   // Setup and configure rf radio
   radio.begin();

examples_RPi/gettingstarted_call_response.cpp

@@ -82,7 +82,7 @@ uint8_t counter = 1;                                                          //
 int main(int argc, char** argv){
 
 
-  printf("RPi/RF24/examples/gettingstarted_call_response\n");
+  cout << "RPi/RF24/examples/gettingstarted_call_response\n";
   radio.begin();
   radio.enableAckPayload();               // Allow optional ack payloads
   radio.enableDynamicPayloads();

examples_RPi/pingpair_dyn.cpp

@@ -79,7 +79,7 @@ int main(int argc, char** argv){
   bool role = 0;
 
   // Print preamble:
-  printf("RF24/examples/pingpair_dyn/\n");
+  cout << "RF24/examples/pingpair_dyn/\n";
 
   // Setup and configure rf radio
   radio.begin();

examples_RPi/transfer.cpp

@@ -79,7 +79,7 @@ int main(int argc, char** argv){
 
   // Print preamble:
 
-  printf("RF24/examples/Transfer/\n");
+  cout << "RF24/examples/Transfer/\n";
 
   radio.begin();                           // Setup and configure rf radio
   radio.setChannel(1);

utility/BBB/RF24_arch_config.h

@@ -25,7 +25,7 @@
 #define _BV(x) (1<<(x))
 #define _SPI spi
 
-#undef SERIAL_DEBUG
+//#undef SERIAL_DEBUG
 #ifdef SERIAL_DEBUG
 #define IF_SERIAL_DEBUG(x) ({x;})
 #else

utility/BBB/spi.cpp

@@ -47,8 +47,14 @@ void SPI::begin(int busNo){
 void SPI::init()
 {
 	int ret;
+    
+    if(this->fd > 0) {
+        close(this->fd);
+    }
+    
 	this->fd = open(this->device.c_str(), O_RDWR);
-	if (this->fd < 0)
+	
+    if (this->fd < 0)
 	{
 		perror("can't open device");
 		abort();