FileOptions -> SourceOptions to work with String paths instead of Files

We check for existence of the sources and (as before) resolve multiple
resources on the classpath if a path is not a File. In addition supports
Spring pseudo-URL prefixes as well as normal URLs as source locations.

In addition sources can now be specified as a directory (searched
recursively by default), or a resource pattern (e.g. app/**/*.groovy).

Fixes gh-207

spring-boot-cli/src/test/resources/dir-sample/code/app.groovy

@@ -0,0 +1,23 @@
+package org.test
+
+@Component
+class Example implements CommandLineRunner {
+
+	@Autowired
+	private MyService myService
+
+	void run(String... args) {
+		println "Hello ${this.myService.sayWorld()} From ${getClass().getClassLoader().getResource('samples/app.groovy')}" 
+	}
+}
+
+
+@Service
+class MyService {
+
+	String sayWorld() {
+		return "World!"
+	}
+}
+
+