Dependency on commons-cli

Spritely has a dependency on the apache commons CLI library. Without the library on the classpath, the following exceptions are thrown and printed to stderr:

Exception in thread "Thread-1" java.lang.NoClassDefFoundError: org/apache/commons/cli/ParseException
	at net.cutgar.ard.concurrent.SpritelyThread.run(SpritelyThread.java:26)
	at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.cli.ParseException
	at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
	... 2 more

On my commons-cli branch I've added the library to the libs/ folder and added it to the classpath (in .classpath).

Feel free to reject this pull request if you feel that this library shouldn't be checked in. I just thought that since I had to make this change to make the game work, you might find it useful.