Add getTimeout accessor method to Stream

Port of https://github.com/arduino/Arduino/pull/4718 to SAMD core.

CHANGELOG

@@ -9,6 +9,7 @@ SAMD CORE
 * Fixed writing LOW to a digital input pin blocking subsequent digitalRead attempts
 * Fixed digitalWrite() unnecessarily activating the pull-up resistor
 * Wire: Slave writes now use TX buffer
+* Added getTimeout() method to Stream.
 
 SAMD CORE 1.6.6 2016.05.19
 

cores/arduino/Stream.h

@@ -66,7 +66,8 @@ class Stream : public Print
 // parsing methods
 
   void setTimeout(unsigned long timeout);  // sets maximum milliseconds to wait for stream data, default is 1 second
-
+  unsigned long getTimeout(void) { return _timeout; }
+  
   bool find(char *target);   // reads data from the stream until the target string is found
   bool find(uint8_t *target) { return find ((char *)target); }
   // returns true if target string is found, false if timed out (see setTimeout)