Worked on the application cache, added request cache, changed some stuff over to be interfaces, added unit tests suite (need mroe) to test all caching providers.

Conflicts:
	src/Umbraco.Core/Cache/CacheProviderBase.cs
	src/Umbraco.Core/Cache/HttpRuntimeCacheProvider.cs
	src/Umbraco.Core/Cache/NullCacheProvider.cs
	src/Umbraco.Core/Cache/StaticCacheProvider.cs

src/Umbraco.Tests/Cache/HttpRequestCacheProviderTests.cs

@@ -0,0 +1,52 @@
+using NUnit.Framework;
+using Umbraco.Core.Cache;
+using Umbraco.Tests.TestHelpers;
+
+namespace Umbraco.Tests.Cache
+{
+    [TestFixture]
+    public class HttpRequestCacheProviderTests : CacheProviderTests
+    {
+        private HttpRequestCacheProvider _provider;
+        private FakeHttpContextFactory _ctx;
+
+        public override void Setup()
+        {
+            base.Setup();
+            _ctx = new FakeHttpContextFactory("http://localhost/test");
+            _provider = new HttpRequestCacheProvider(() => _ctx.HttpContext);
+        }
+
+        internal override ICacheProvider Provider
+        {
+            get { return _provider; }
+        }
+
+        protected override int GetTotalItemCount
+        {
+            get { return _ctx.HttpContext.Items.Count; }
+        }
+    }
+
+    [TestFixture]
+    public class StaticCacheProviderTests : CacheProviderTests
+    {
+        private StaticCacheProvider _provider;        
+
+        public override void Setup()
+        {
+            base.Setup();
+            _provider = new StaticCacheProvider();
+        }
+
+        internal override ICacheProvider Provider
+        {
+            get { return _provider; }
+        }
+
+        protected override int GetTotalItemCount
+        {
+            get { return _provider.StaticCache.Count; }
+        }
+    }
+}