Allow custom restart pollInterval and quietPeriod

Allow the pollInterval and the quietPeriod of the filewatcher to be
configured.

Fixes gh-3139

spring-boot-samples/spring-boot-sample-devtools/src/main/java/demo/SampleDevToolsApplication.java

@@ -26,5 +26,4 @@ public class SampleDevToolsApplication extends WebMvcAutoConfigurationAdapter {
 	public static void main(String[] args) {
 		SpringApplication.run(SampleDevToolsApplication.class, args);
 	}
-
 }