Refactor XSkull API

- Fix `XSkull.TEXTURES` constant (old clients require the HTTP protocol to render properly).
- Add 1.8 remap for MinecraftServer getter.
- Deprecate `XSkull.applySkin` in favor of `XSkull#of`
- Remove cache for profiles generated from base64 (#254).
- Log exceptions using debug level.

src/main/java/com/cryptomorin/xseries/XItemStack.java

@@ -21,6 +21,7 @@
  */
 package com.cryptomorin.xseries;
 
+import com.cryptomorin.xseries.skull.XSkull;
 import com.google.common.base.Enums;
 import com.google.common.base.Strings;
 import com.google.common.collect.Multimap;

src/main/java/com/cryptomorin/xseries/skull/Action.java

@@ -0,0 +1,48 @@
+package com.cryptomorin.xseries.skull;
+
+import com.mojang.authlib.GameProfile;
+
+import javax.annotation.Nonnull;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.atomic.AtomicInteger;
+
+public class Action<T> {
+    private static final ExecutorService EXECUTOR = Executors.newFixedThreadPool(2, new ThreadFactory() {
+        private final AtomicInteger count = new AtomicInteger();
+        @Override
+        public Thread newThread(final @Nonnull Runnable run) {
+            final Thread thread = new Thread(run);
+            thread.setName("Profile Lookup Executor #" + this.count.getAndIncrement());
+            thread.setUncaughtExceptionHandler((t, throwable) ->
+                    XSkull.LOGGER.debug("Uncaught exception in thread {}", t.getName(), throwable));
+            return thread;
+        }
+    });
+
+    private final Instruction<T> inputHandle;
+
+    protected Action(Instruction<T> handle) {
+        this.inputHandle = handle;
+    }
+
+    public T setter() {
+        return inputHandle.setter.setProfile(getter());
+    }
+
+    public GameProfile getter() {
+        return inputHandle.type == null
+                ? XSkull.profileFromString(inputHandle.input)
+                : XSkull.profileFromValueType(inputHandle.type, inputHandle.input);
+    }
+
+    public CompletableFuture<T> asyncSetter() {
+        return CompletableFuture.supplyAsync(this::setter, EXECUTOR);
+    }
+
+    public CompletableFuture<GameProfile> asyncGetter() {
+        return CompletableFuture.supplyAsync(this::getter, EXECUTOR);
+    }
+}

src/main/java/com/cryptomorin/xseries/skull/Instruction.java

@@ -0,0 +1,49 @@
+package com.cryptomorin.xseries.skull;
+
+import java.util.UUID;
+
+public class Instruction<T> {
+
+    protected String input;
+    protected ValueType type;
+    protected Setter<T> setter;
+
+    protected Instruction(Setter<T> setter) {
+        this.setter = setter;
+    }
+
+    public Action<T> from(String input) {
+        this.input = input;
+        return new Action<>(this);
+    }
+
+    public Action<T> fromUUID(UUID input) {
+        this.input = input.toString();
+        this.type = ValueType.UUID;
+        return new Action<>(this);
+    }
+
+    public Action<T> fromUsername(String input) {
+        this.input = input;
+        this.type = ValueType.USERNAME;
+        return new Action<>(this);
+    }
+
+    public Action<T> fromBase64(String input) {
+        this.input = input;
+        this.type = ValueType.BASE64;
+        return new Action<>(this);
+    }
+
+    public Action<T> fromURL(String input) {
+        this.input = input;
+        this.type = ValueType.TEXTURE_URL;
+        return new Action<>(this);
+    }
+
+    public Action<T> fromHash(String input) {
+        this.input = input;
+        this.type = ValueType.TEXTURE_HASH;
+        return new Action<>(this);
+    }
+}

src/main/java/com/cryptomorin/xseries/skull/Setter.java

@@ -0,0 +1,8 @@
+package com.cryptomorin.xseries.skull;
+
+import com.mojang.authlib.GameProfile;
+
+@FunctionalInterface
+public interface Setter<T> {
+    T setProfile(GameProfile profile);
+}

src/main/java/com/cryptomorin/xseries/skull/ValueType.java

@@ -0,0 +1,28 @@
+package com.cryptomorin.xseries.skull;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.Arrays;
+import java.util.regex.Pattern;
+
+public enum ValueType {
+
+    TEXTURE_HASH(Pattern.compile("[0-9a-z]{55,70}")),
+    TEXTURE_URL(Pattern.compile(Pattern.quote(XSkull.TEXTURES) + TEXTURE_HASH.pattern)),
+    BASE64(Pattern.compile("[-A-Za-z0-9+/]{100,}={0,3}")),
+    UUID(Pattern.compile("[A-F\\d]{8}-[A-F\\d]{4}-4[A-F\\d]{3}-([89AB])[A-F\\d]{3}-[A-F\\d]{12}", Pattern.CASE_INSENSITIVE)),
+    USERNAME(Pattern.compile("[A-Za-z0-9_]{1,16}"));
+
+    private final Pattern pattern;
+
+    ValueType(Pattern compile) {
+        this.pattern = compile;
+    }
+
+    @Nullable
+    public static ValueType get(@Nonnull String identifier) {
+        return Arrays.stream(ValueType.values())
+                .filter(value -> value.pattern.matcher(identifier).matches())
+                .findFirst().orElse(null);
+    }
+}