Revert "Removing Leonardo (and Mouse/Keyboard examples) for Arduino 1.0 release."

This reverts commit dca1dc429a.

build/shared/examples/9.Keyboard/KeyboardSerial/KeyboardSerial.ino

@@ -0,0 +1,33 @@
+/* 
+ Keyboard test
+ 
+ Reads a byte from the serial port, sends a keystroke back.
+ The sent keystroke is one higher than what's received, e.g.
+ if you send a, you get b, send A you get B, and so forth.
+ 
+ The circuit:
+ * none
+ 
+ created 21 Oct 2011
+ by Tom Igoe
+ 
+This example code is in the public domain.
+ 
+ http://www.arduino.cc/en/Tutorial/KeyboardSerial
+ */
+
+void setup() {
+  // open the serial port:
+Serial.begin(9600);
+}
+
+void loop() {
+  // check for incoming serial data:
+  if (Serial.available() > 0) {
+    // read incoming serial data:
+    char inChar = Serial.read();
+    // Type the next ASCII value from what you received:
+    Keyboard.write(inChar+1);
+  }  
+}
+