Wire: Define default timeout settings in Wire.h

Previously, these were implicit in the default values of some global
variables. Now, the default timeout is defined in Wire.h, which:
 - Makes it easier to change later
 - Allows sketches to detect the default timeout value

Author: matthijskooijman

libraries/Wire/src/Wire.cpp

@@ -64,6 +64,8 @@ void TwoWire::begin(void)
   twi_init();
   twi_attachSlaveTxEvent(onRequestService); // default callback must exist
   twi_attachSlaveRxEvent(onReceiveService); // default callback must exist
+
+  twi_setTimeoutInMicros(WIRE_DEFAULT_TIMEOUT, WIRE_DEFAULT_RESET_WITH_TIMEOUT);
 }
 
 void TwoWire::begin(uint8_t address)

libraries/Wire/src/Wire.h

@@ -34,6 +34,10 @@
 // and clearWireTimeoutFlag()
 #define WIRE_HAS_TIMEOUT 1
 
+// When not configured, these settings are used for the timeout
+#define WIRE_DEFAULT_TIMEOUT 0
+#define WIRE_DEFAULT_RESET_WITH_TIMEOUT false
+
 class TwoWire : public Stream
 {
   private: