Added @NonNull on parameters feature (issue 514),

including docs and changelog.

test/transform/resource/before/NonNullOnParameter.java

@@ -0,0 +1,30 @@
+class NonNullOnParameter extends Thread {
+	NonNullOnParameter(@lombok.NonNull String arg) {
+		this(arg, "");
+	}
+	
+	NonNullOnParameter(@lombok.NonNull String arg, @lombok.NonNull String arg2) {
+		super(arg);
+		if (arg == null) throw new NullPointerException();
+	}
+	
+	public void test2(@lombok.NonNull String arg, @lombok.NonNull String arg2, @lombok.NonNull String arg3) {
+		if (arg2 == null) {
+			throw new NullPointerException("arg2");
+		}
+		if (arg == null) System.out.println("Hello");
+	}
+	
+	public void test3(@lombok.NonNull String arg) {
+		if (arg != null) throw new IllegalStateException();
+	}
+	
+	public void test(@lombok.NonNull String stringArg, @lombok.NonNull String arg2, @lombok.NonNull int primitiveArg) {
+		
+	}
+	
+	public void test(@lombok.NonNull String arg) {
+		System.out.println("Hey");
+		if (arg == null) throw new NullPointerException();
+	}
+}