NH-3807 - Guard on uses of HttpContext since CoreCli doesn't have it.

Author: ngbrown

src/NHibernate/Context/ReflectiveHttpContext.cs

@@ -1,3 +1,5 @@
+#if FEATURE_WEB_SESSION_CONTEXT
+
 using System;
 using System.Collections;
 using System.Linq.Expressions;
@@ -54,4 +56,6 @@ private static void CreateHttpContextItemsGetter()
 			HttpContextItemsGetter = (Func<object, IDictionary>) Expression.Lambda(itemsProperty, contextParam).Compile();
 		}
 	}
-}
+}
+
+#endif

src/NHibernate/Context/WebSessionContext.cs

@@ -1,3 +1,5 @@
+#if FEATURE_WEB_SESSION_CONTEXT
+
 using System;
 using System.Collections.Generic;
 using NHibernate.Engine;
@@ -26,3 +28,5 @@ protected override void SetMap(IDictionary<ISessionFactoryImplementor, ISession>
 		}
 	}
 }
+
+#endif

src/NHibernate/Impl/SessionFactoryImpl.cs

@@ -1254,8 +1254,10 @@ private ICurrentSessionContext BuildCurrentSessionContext()
 #endif
 				case "thread_static":
 					return new ThreadStaticSessionContext(this);
+#if FEATURE_WEB_SESSION_CONTEXT
 				case "web":
 					return new WebSessionContext(this);
+#endif
 #if FEATURE_REMOTING
 				case "wcf_operation":
 					return new WcfOperationSessionContext(this);