Adding a couple of release notes for the Leonardo.

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

These will return, but the code isn't finished yet so I don't want to include it.

Switching to RXTX-2.1-7r2 on 64-bit Linux (working version).

This also means we don't need a separate RXTXcomm.jar file for 64-bit Linux.
(cherry picked from commit 24e62aa)

Updating Mac Info.plist version to 1.0-rc2.

Updating Mac OS X Info.plist (.app) version to 1.0-beta4.

Fixes to compile under Java 1.5 (on my Linux machine).

Following symlinks in arduino launch script for Linux.

Updating version to 0021.

Updating version to 0020.

Tagging release 0019.