Added thread IsBackground unit test

STPTests/TestThreadIsBackground.cs

@@ -0,0 +1,47 @@
+using System.Threading;
+using NUnit.Framework;
+using Amib.Threading;
+
+namespace SmartThreadPoolTests
+{
+	/// <summary>
+    /// Summary description for TestThreadIsBackground.
+	/// </summary>
+	[TestFixture]
+    [Category("TestThreadIsBackground")]
+	public class TestThreadIsBackground
+	{
+		[Test]
+        public void TestIsBackground()
+		{
+            CheckIsBackground(true);
+		}
+
+		[Test]
+        public void TestNotIsBackground()
+		{
+            CheckIsBackground(false);
+		}
+
+        private static void CheckIsBackground(bool isBackground)
+	    {
+	        STPStartInfo stpStartInfo = new STPStartInfo();
+	        stpStartInfo.AreThreadsBackground = isBackground;
+
+	        SmartThreadPool stp = new SmartThreadPool(stpStartInfo);
+
+            IWorkItemResult<bool> wir = stp.QueueWorkItem(() => GetCurrentThreadIsBackground());
+
+	        bool resultIsBackground = wir.GetResult();
+
+	        stp.WaitForIdle();
+
+            Assert.AreEqual(isBackground, resultIsBackground);
+	    }
+
+	    private static bool GetCurrentThreadIsBackground()
+	    {
+	        return Thread.CurrentThread.IsBackground;
+	    }
+	}
+}