Add CircuitBreaker Initial based on akka 2.0.5

- Add passing tests from akka 2.0.5
- Add CircuitBreakerState.cs with Open, HalfOpen, and Closed states
- Add AtomicState which extends AtomicLong (mirrors functionality of State trait)
- Add OpenCircuitException
- Add CircuitBreaker documentation
- Remove Scheduler from current implementation
- Remove inappropriate xmldoc on illegalstateexception
- Update flow on AtomicState::CallThrough method to be clearer and more closely match original
- Add clarifying comments on "Fire and forget" NotifyTransitionListeners

src/Akka.sln

@@ -2,6 +2,8 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio 14
 VisualStudioVersion = 14.0.22823.1
+# Visual Studio 2013
+VisualStudioVersion = 12.0.31101.0
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Examples", "Examples", "{69279534-1DBA-4115-BF8B-03F77FC8125E}"
 EndProject
@@ -211,6 +213,10 @@ EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Akka.MultiNodeTests", "core\Akka.MultiNodeTests\Akka.MultiNodeTests.csproj", "{F0781BEA-5BA0-4AF0-BB15-E3F209B681F5}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PersistenceBenchmark", "benchmark\PersistenceBenchmark\PersistenceBenchmark.csproj", "{39E6F51F-FA1E-4C62-B8F8-19065DE6D55D}"
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{A59BAE84-70E2-46A0-9E26-7413C103E2D7}"
+	ProjectSection(SolutionItems) = preProject
+		WebEssentials-Settings.json = WebEssentials-Settings.json
+	EndProjectSection
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution

src/core/Akka.TestKit/Akka.TestKit.csproj

@@ -111,6 +111,7 @@
     <Compile Include="TestActors\BlackHoleActor.cs" />
     <Compile Include="TestActors\EchoActor.cs" />
     <Compile Include="TestBarrier.cs" />
+    <Compile Include="TestBreaker.cs" />
     <Compile Include="TestFSMRef.cs" />
     <Compile Include="ITestKitAssertions.cs" />
     <Compile Include="MessageEnvelope.cs" />

src/core/Akka.TestKit/TestBreaker.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Linq;
+using System.Runtime.Serialization;
+using System.Threading;
+using System.Threading.Tasks;
+using Akka.Pattern;
+
+namespace Akka.TestKit
+{
+    public class TestBreaker
+    {
+        public CountdownEvent HalfOpenLatch { get; private set; }
+        public CountdownEvent OpenLatch { get; private set; }
+        public CountdownEvent ClosedLatch { get; private set; }
+        public CircuitBreaker Instance { get; private set; }
+
+        public TestBreaker( CircuitBreaker instance )
+        {
+            HalfOpenLatch = new CountdownEvent( 1 );
+            OpenLatch = new CountdownEvent( 1 );
+            ClosedLatch = new CountdownEvent( 1 );
+            Instance = instance;
+            Instance.OnClose( ( ) => { if ( !ClosedLatch.IsSet ) ClosedLatch.Signal( ); } )
+                    .OnHalfOpen( ( ) => { if ( !HalfOpenLatch.IsSet ) HalfOpenLatch.Signal( ); } )
+                    .OnOpen( ( ) => { if ( !OpenLatch.IsSet ) OpenLatch.Signal( ); } );
+        }
+
+
+    }
+}

src/core/Akka.Tests/Akka.Tests.csproj

@@ -150,6 +150,7 @@
     <Compile Include="MatchHandler\MatchHandlerBuilderTests.cs" />
     <Compile Include="MatchHandler\PartialActionBuilderTests.cs" />
     <Compile Include="Pattern\BackoffSupervisorSpec.cs" />
+    <Compile Include="Pattern\CircuitBreakerSpec.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Routing\BroadcastSpec.cs" />
     <Compile Include="Routing\ConsistentHashingRouterSpec.cs" />