Updating for Java 11

Also continuing updates to take advantage of the newer
Java version we build against, fix typos in documentation, and
switch to explicit API annotations to indicate project entry
points.

src/main/java/org/deepsymmetry/beatlink/data/ColorItem.java

@@ -1,26 +1,31 @@
 package org.deepsymmetry.beatlink.data;
 
+import org.apiguardian.api.API;
+
 import java.awt.*;
 
 /**
- * Represents a track color label. This is a specialized {@link SearchableItem}, since in addition to a specific color,
+ * <p>Represents a track color label. This is a specialized {@link SearchableItem}, since in addition to a specific color,
  * it has an ID and label that can be used as a way to select tracks in a dynamic playlist request,
- * and on which playlists can be sorted.
+ * and on which playlists can be sorted.</p>
  *
- * A simple immutable value class.
+ * <p>A simple immutable value class.</p>
  *
  * @author James Elliott
  */
+@API(status = API.Status.STABLE)
 public class ColorItem extends SearchableItem {
 
     /**
      * The color that is represented by this item.
      */
+    @API(status = API.Status.STABLE)
     public final Color color;
 
     /**
      * The name of the color represented by this item, for textual display.
      */
+    @API(status = API.Status.STABLE)
     public final String colorName;
 
     /**
@@ -30,6 +35,7 @@ public class ColorItem extends SearchableItem {
      * @param id the database ID associated with this item, for searches
      * @param label the text label used to show this item to the user
      */
+    @API(status = API.Status.STABLE)
     public ColorItem(int id, String label) {
         super(id, label);
         color = colorForId(id);
@@ -69,6 +75,7 @@ public boolean equals(Object obj) {
      * @param color a color to be examined
      * @return {@code true} if the color represents the lack of a color assignment
      */
+    @API(status = API.Status.STABLE)
     public static boolean isNoColor(Color color) {
         return color.getAlpha() == 0;
     }
@@ -83,6 +90,7 @@ public static boolean isNoColor(Color color) {
      *
      * @return the color that should be displayed (or which the UI should be tinted with)
      */
+    @API(status = API.Status.STABLE)
     public static Color colorForId(int colorId) {
         switch (colorId) {
 
@@ -125,6 +133,7 @@ public static Color colorForId(int colorId) {
      *
      * @return the color that should be displayed (or which the UI should be tinted with)
      */
+    @API(status = API.Status.STABLE)
     public static String colorNameForId(int colorId) {
         switch (colorId) {
             case 0: