Add _BV() macro.

Author: jgfoster

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Changed
 - Change 266 files from CRLF to LF.
+- Add `_BV()` macro.
 
 ### Deprecated
 

cpp/arduino/Arduino.h

@@ -50,10 +50,7 @@ typedef uint8_t byte;
 
 typedef unsigned int word;
 
-#define bit(b) (1UL << (b))
-
-
-
+#define _BV(bit) (1 << (bit))
 
 // Get the bit location within the hardware port of the given virtual pin.
 // This comes from the pins_*.c file for the active board configuration.