refactor out into common create SringXDTemplate method.

The JobUtils and StreamUtils command could probably not be static helper classes, but instead a 'JobCommands' and 'StreamCommands' class that receives an instance of a fully configured SpringXDTemplate or the URL of the admin server.  Looking at a method like

	public static void destroyAllStreams(final URL adminServer) {
		Assert.notNull(adminServer, "The admin server must be specified.");
		createSpringXDTemplate(adminServer).streamOperations().destroyAll();
	}

It isn't clear why the caller just couldn't call SpringXDTemplate directly....    I notice StreamTemplate doesn't do asserts on the String values passed in....