Added function on WString class to export char ptr

cores/arduino/Print.cpp

@@ -53,11 +53,8 @@ size_t Print::print(const __FlashStringHelper *ifsh)
 
 size_t Print::print(const String &s)
 {
-  size_t n = 0;
-  for (uint16_t i = 0; i < s.length(); i++) {
-    n += write(s[i]);
-  }
-  return n;
+  write((const uint8_t*)s.c_str(), s.length());
+  return s.length();
 }
 
 size_t Print::print(const char str[])

cores/arduino/WString.cpp

@@ -642,4 +642,8 @@ long String::toInt(void) const
 	return 0;
 }
 
+char* String::c_str() const
+{
+	return buffer;
+}
 

cores/arduino/WString.h

@@ -169,6 +169,7 @@ public:
 
 	// parsing/conversion
 	long toInt(void) const;
+	char* c_str() const;
 
 protected:
 	char *buffer;	        // the actual char array