AppLauncher should remain in headless mode when running from CLI with arguments

[rbouckaert]

Currently, it initialises JavaFX, which results in the cursor being refocused on OS X. This is annoying when trying to run many apps in the background.

Proposed solution: update shell script for applauncher like so:

if [ "$#" -gt 1 ]; then
    HEADLESS="-Djava.awt.headless=true"
else
    HEADLESS=""
fi

# and then we can add it to the call below:
if [ -n "$BEAST_EXTRA_LIBS" ]; then 
  "$JAVA" $HEADLESS -Dlauncher.wait.for.exit=true -Xss256m -Xmx24g -Djava.library.path="$BEAST_EXTRA_LIBS" -Duser.language=en -cp "$BEAST_LIB/launcher.jar" beast.pkgmgmt.launcher.AppLauncherLauncher $*
else	
  "$JAVA" $HEADLESS -Dlauncher.wait.for.exit=true -Xss256m -Xmx24g -Duser.language=en -cp "$BEAST_LIB/launcher.jar" beast.pkgmgmt.launcher.AppLauncherLauncher $*
fi