Adding new system strings

[bchong95]

Added new system strings.

Tests already exist in:

JsonWriterTests.cs and JsonReaderTests.cs

SystemStringTest

It uses reflection so it automatically picks up the full set of strings:

        [TestMethod]
        [Owner("brchon")]
        public void SystemStringTest()
        {
            Type jsonBinaryEncodingType = typeof(JsonBinaryEncoding);
            FieldInfo systemStringsFieldInfo = jsonBinaryEncodingType.GetField("SystemStrings", BindingFlags.NonPublic | BindingFlags.Static);
            string[] systemStrings = (string[])systemStringsFieldInfo.GetValue(null);
            Assert.IsNotNull(systemStrings, "Failed to get system strings using reflection");

            int systemStringId = 0;
            foreach (string systemString in systemStrings)
            {
                string expectedString = "\"" + systemString + "\"";
                byte[] binaryOutput =
                {
                    BinaryFormat,
                    (byte)(JsonBinaryEncoding.TypeMarker.SystemString1ByteLengthMin + ((int)systemStringId)),
                };

                JsonTokenInfo[] tokensToWrite =
                {
                    JsonTokenInfo.String(systemString)
                };

                this.VerifyWriter(tokensToWrite, expectedString);
                this.VerifyWriter(tokensToWrite, binaryOutput);
                systemStringId++;
            }
        }

[kirankumarkolli]

Please port this to release branch also.