polishing documentation
Change explicit bean type to concrete NamedParameterJdbcTemplate

Fixes gh-447
Use org.springframework.boot groupId in spring-boot-samples

Use org.springframework.boot instead of ${project.groupId}
groupId in order to make it easier to use spring-boot-samples
modules as a starting point for new projects.
Fix typo
fixup yaml codeblock
Allow non-string return from health query
fix link to install.txt

Explicitly link to install.txt in source repo to avoid issues on projects.spring.io with a broken relative link
... also fix this for rendered markdown on GH itself :-)
Added testWhileIdle etc.

Fixes gh-463
Add templates/** to list of default includes for CLI jars

Boot promotes the use of a templates directory for housing view
templates. Include this directory by default when building a jar file
from a CLI app.

Fixes #455
More care taken with management.contextPath

The management.contextPath property should now be respected in a
secure application, whether or not the management.port is different.

Added some test cases in the sample to verify.

Fixes gh-469
Remove duplicate resources from classpath

We had been making a special case for logback.xml anyway, so
extending that to simply deleting recursively all of
src/main/resources (or equivalent) from target/classes (or
equivalent) seems like it's perfectly justifiable.

Fixes gh-451
Support for maxWait, jdbcInterceptors and validationInterval

Fixes gh-470
Add exlcusion to httpcomponents dependency
Refactor SpringApplication Environment config hooks

Per discussion: fixes gh-467
Fix typo in ConfigFileAppListener#addProper(=>t)ySources
Add @IntegrationTest annotation for test classes

Allowing use of embededded container in @SpringApplicationConfiguration
tests, e.g.

```
@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = Config.class)
@WebAppConfiguration
@IntegrationTest
public class SpringApplicationIntegrationTestTests {

	@Test
	public void nestedConfigClasses() {
		String body = new RestTemplate().getForObject("http://localhost:8080/",
				String.class);
		assertEquals("Hello World", body);
	}

	@Configuration
	@EnableWebMvc
	@RestController
	protected static class Config {

		@Bean
		public DispatcherServlet dispatcherServlet() {
			return new DispatcherServlet();
		}

		@Bean
		public EmbeddedServletContainerFactory embeddedServletContainer() {
			return new TomcatEmbeddedServletContainerFactory();
		}

		@RequestMapping("/")
		public String home() {
			return "Hello World";
		}

	}

}
```

Fixes gh-473
Convert all sample tests to @IntegrationTest where appropriate

Makes them a lot more readable IMO, and also enables @Autowiring
from the context into the test case (sweeet). I added @DirtiesContext
to all of them as well to be on the safe side, but possbly that can be
optimized in some way as well.
Add support for Apache HttpClient if available
Fix some broken tests in empty new environments
More defensive testing of tmpdir