HttpScheme class

Motivation:
The HTTP schemes defined by https://tools.ietf.org/html/rfc7230 don't have a common representation in Netty.

Modifications:
- Add a class to represent HttpScheme

Result:
The HTTP Scheme is now defined in 1 common location.

codec-http/src/main/java/io/netty/handler/codec/http/HttpScheme.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2015 The Netty Project
+ *
+ * The Netty Project licenses this file to you under the Apache License,
+ * version 2.0 (the "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at:
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ */
+package io.netty.handler.codec.http;
+
+import io.netty.util.AsciiString;
+
+/**
+ * Defines the common schemes used for the HTTP protocol as defined by
+ * <a href="https://tools.ietf.org/html/rfc7230">rfc7230</a>.
+ */
+public final class HttpScheme {
+    public static final HttpScheme HTTP = new HttpScheme(80, "http");
+    public static final HttpScheme HTTPS = new HttpScheme(443, "https");
+
+    private final int port;
+    private final AsciiString name;
+
+    private HttpScheme(int port, String name) {
+        this.port = port;
+        this.name = new AsciiString(name);
+    }
+
+    public AsciiString name() {
+        return name;
+    }
+
+    public int port() {
+        return port;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (!(o instanceof HttpScheme)) {
+            return false;
+        }
+        HttpScheme other = (HttpScheme) o;
+        return other.port() == port && other.name().equals(name);
+    }
+
+    @Override
+    public int hashCode() {
+        return port * 31 + name.hashCode();
+    }
+
+    @Override
+    public String toString() {
+        return name.toString();
+    }
+}