Moved Print::write() implementation into Print.cpp

JsonGenerator/Print.h

@@ -15,15 +15,7 @@ public:
 
     virtual size_t write(uint8_t c) = 0;
 
-    size_t write(const char* s)
-    {
-        size_t n = 0;
-        while (*s)
-        {
-            n += write(*s++);
-        }
-        return n;
-    }
+    size_t write(const char* s);
 };
 
 #else