Contextual: push setContext default impl to iface

Thank you Java 8.

Author: ctrueden

src/main/java/org/scijava/AbstractContextual.java

@@ -62,10 +62,4 @@ public Context context() {
 	public Context getContext() {
 		return context;
 	}
-
-	@Override
-	public void setContext(final Context context) {
-		context.inject(this);
-	}
-
 }

src/main/java/org/scijava/Contextual.java

@@ -69,12 +69,14 @@ public interface Contextual {
 	 * </p>
 	 * 
 	 * @see Context#inject(Object)
-	 * @see AbstractContextual for an example of how to implement this interface
 	 * @throws IllegalStateException If the object already has a context.
 	 * @throws IllegalArgumentException If the object has a required
 	 *           {@link Service} parameter (see {@link Parameter#required()})
 	 *           which is not available from the context.
 	 */
-	void setContext(Context context);
+	default void setContext(final Context context) {
+		context.inject(this);
+	}
+
 
 }