Apply animal sniffer to entire build

Move animal sniffer configuration out of spring-boot-dependencies to
spring-boot-parent and apply it to all projects.

See gh-716

spring-boot-tools/spring-boot-loader/pom.xml

@@ -20,6 +20,11 @@
 	</properties>
 	<dependencies>
 		<!-- Must never have compile/runtime time dependencies -->
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-core</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.slf4j</groupId>
 			<artifactId>jcl-over-slf4j</artifactId>

spring-boot-tools/spring-boot-loader/src/main/java/org/springframework/boot/loader/LaunchedURLClassLoader.java

@@ -27,6 +27,7 @@ import java.util.Enumeration;
 
 import org.springframework.boot.loader.jar.Handler;
 import org.springframework.boot.loader.jar.JarFile;
+import org.springframework.lang.UsesJava7;
 
 /**
  * {@link ClassLoader} used by the {@link Launcher}.
@@ -224,6 +225,7 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 		}
 	}
 
+	@UsesJava7
 	private static LockProvider setupLockProvider() {
 		try {
 			ClassLoader.registerAsParallelCapable();
@@ -248,6 +250,7 @@ public class LaunchedURLClassLoader extends URLClassLoader {
 	/**
 	 * Java 7 specific {@link LockProvider}.
 	 */
+	@UsesJava7
 	private static class Java7LockProvider extends LockProvider {
 
 		@Override