Converted PBKDF2 and RC2, enabled tests, deleted legacy Cipher file

Also made DESDecrypt test pass

src/core/operations/DerivePBKDF2Key.mjs

@@ -0,0 +1,77 @@
+/**
+ * @author n1474335 [n1474335@gmail.com]
+ * @copyright Crown Copyright 2016
+ * @license Apache-2.0
+ */
+
+import Operation from "../Operation";
+import Utils from "../Utils";
+import forge from "node-forge/dist/forge.min.js";
+
+/**
+ * Derive PBKDF2 key operation
+ */
+class DerivePBKDF2Key extends Operation {
+
+    /**
+     * DerivePBKDF2Key constructor
+     */
+    constructor() {
+        super();
+
+        this.name = "Derive PBKDF2 key";
+        this.module = "Ciphers";
+        this.description = "PBKDF2 is a password-based key derivation function. It is part of RSA Laboratories' Public-Key Cryptography Standards (PKCS) series, specifically PKCS #5 v2.0, also published as Internet Engineering Task Force's RFC 2898.<br><br>In many applications of cryptography, user security is ultimately dependent on a password, and because a password usually can't be used directly as a cryptographic key, some processing is required.<br><br>A salt provides a large set of keys for any given password, and an iteration count increases the cost of producing keys from a password, thereby also increasing the difficulty of attack.<br><br>If you leave the salt argument empty, a random salt will be generated.";
+        this.inputType = "string";
+        this.outputType = "string";
+        this.args = [
+            {
+                "name": "Passphrase",
+                "type": "toggleString",
+                "value": "",
+                "toggleValues": ["UTF8", "Latin1", "Hex", "Base64"]
+            },
+            {
+                "name": "Key size",
+                "type": "number",
+                "value": 128
+            },
+            {
+                "name": "Iterations",
+                "type": "number",
+                "value": 1
+            },
+            {
+                "name": "Hashing function",
+                "type": "option",
+                "value": ["SHA1", "SHA256", "SHA384", "SHA512", "MD5"]
+            },
+            {
+                "name": "Salt",
+                "type": "toggleString",
+                "value": "",
+                "toggleValues": ["Hex", "UTF8", "Latin1", "Base64"]
+            }
+        ];
+    }
+
+    /**
+     * @param {string} input
+     * @param {Object[]} args
+     * @returns {string}
+     */
+    run(input, args) {
+        const passphrase = Utils.convertToByteString(args[0].string, args[0].option),
+            keySize = args[1],
+            iterations = args[2],
+            hasher = args[3],
+            salt = Utils.convertToByteString(args[4].string, args[4].option) ||
+                forge.random.getBytesSync(keySize),
+            derivedKey = forge.pkcs5.pbkdf2(passphrase, salt, iterations, keySize / 8, hasher.toLowerCase());
+
+        return forge.util.bytesToHex(derivedKey);
+    }
+
+}
+
+export default DerivePBKDF2Key;