Adding shoes-guard script
Adding shoes-guard script

On OS X unfortunately we have to pass the -J-XstartOnFirstThread flag along to
JRuby and the JVM when starting up, otherwise the SWT tests fail badly. Even
worse, apparently setting that flag will cause other OS's to crash.

Everyone can use bin/shoes-guard to start up Guard, and those on OS X will get
the necessary flag set, while other OS's won't.

thescientician/lightning-timer,thescientician/lightning-timer,thescientician/lightning-timer