Don't throw an exception when attempting to leave an unentered critical section, for consistency with simplsharp

ICD.Common.Utils.Tests/SafeCriticalSectionTest.cs

@@ -32,6 +32,9 @@ namespace ICD.Common.Utils.Tests
 		[Test]
 		public void LeaveTest()
 		{
+			SafeCriticalSection section = new SafeCriticalSection();
+			Assert.DoesNotThrow(() => section.Leave());
+
 			Assert.Inconclusive();
 		}
 

ICD.Common.Utils/SafeCriticalSection.Standard.cs

@@ -20,7 +20,8 @@ namespace ICD.Common.Utils
 		/// </summary>
 		public void Leave()
 		{
-			Monitor.Exit(this);
+			if (Monitor.IsEntered(this))
+				Monitor.Exit(this);
 		}
 
 		/// <summary>