Added unit tests (all passing unfortunately)

UI improvements
Write mode still doesn't work

ModernKeePassLib.Test/Keys/KcpPasswordTests.cs

@@ -0,0 +1,33 @@
+using NUnit.Framework;
+using System;
+
+#if KeePassLib
+using KeePassLib.Keys;
+#else
+using ModernKeePassLibPCL.Keys;
+#endif
+
+namespace ModernKeePassLib.Test.Shared.Keys
+{
+  [TestFixture ()]
+  public class KcpPasswordTests
+  {
+    const string testPassword = "password";
+
+    [Test ()]
+    public void TestConstruct ()
+    {
+      var expectedHash = new byte[32] {
+        0x5E, 0x88, 0x48, 0x98, 0xDA, 0x28, 0x04, 0x71,
+        0x51, 0xD0, 0xE5, 0x6F, 0x8D, 0xC6, 0x29, 0x27,
+        0x73, 0x60, 0x3D, 0x0D, 0x6A, 0xAB, 0xBD, 0xD6,
+        0x2A, 0x11, 0xEF, 0x72, 0x1D, 0x15, 0x42, 0xD8
+      };
+
+      var key = new KcpPassword (testPassword);
+      var keyData = key.KeyData.ReadData ();
+      Assert.That (keyData, Is.EqualTo (expectedHash));
+    }
+  }
+}
+