reworked classpath option such that user-supplied glob patterns are resolved

Sorry for all the PRs, I'd kind of rushed the classpath stuff to suit my needs at the time originally.

This enables people to use glob patterns in the classpath option, e.g.:

	var gremlin = new require('gremlin')({
		classpath: [
			path.join(__dirname, 'lib', '*.jar')
		],
		options: [
			'-Dlog4j.configuration=file:' + path.resolve(__dirname, './log4j.properties'),
			'-Dlogback.configurationFile=' + path.resolve(__dirname, './logback.xml'),
		]
	});