Relocate projects to spring-boot-project

Move projects to better reflect the way that Spring Boot is released.

The following projects are under `spring-boot-project`:

  - `spring-boot`
  - `spring-boot-autoconfigure`
  - `spring-boot-tools`
  - `spring-boot-starters`
  - `spring-boot-actuator`
  - `spring-boot-actuator-autoconfigure`
  - `spring-boot-test`
  - `spring-boot-test-autoconfigure`
  - `spring-boot-devtools`
  - `spring-boot-cli`
  - `spring-boot-docs`

See gh-9316

spring-boot-project/spring-boot-cli/samples/http.groovy

@@ -0,0 +1,24 @@
+package org.test
+
+@Grab("org.codehaus.groovy.modules.http-builder:http-builder:0.5.2") // This one just to test dependency resolution
+import groovyx.net.http.*
+
+@Controller
+class Example implements CommandLineRunner {
+
+	@Autowired
+	ApplicationContext context;
+
+	@RequestMapping("/")
+	@ResponseBody
+	public String helloWorld() {
+		return "World!"
+	}
+
+	void run(String... args) {
+		def port = context.webServer.port;
+		def world = new RESTClient("http://localhost:" + port).get(path:"/").data.text
+		print "Hello " + world
+	}
+
+}