SvcHttpHandler maintains a mapping of HttpContext to ManualResetEvent. Entries are
removed from the cache in EndHttpRequest. The code makes sure the context exists in
the cache before attempting to access it.

* bugfix:
  [asp.net] Make sure output_stream is not null before using it

It is possible that some code will still attempt to access the HttpResponse instance
after ReleaseResources got called. This patch prevents NREX in such cases.

Pass the listener as it's own async state so that we avoid potential null derefs in the callback. Also wrap the BeginAccept and EndAccept calls in their own try/catches in case they throw an exception.

The problem is that DispatchRuntime.Type is a service implementation type
that could implement two or more contract interfaces, and it was in random
order how ServiceProxyGenerator picks up the contract type. Now it looks
for correct contract type instead of the service type by exactly looking
for the target contract in the endpoint (dispatcher).

In some embedding scenarios, mscorlib.dll may be present in a non-standard
location (outside of MONO_PATH) or with an alternate filename.

Use the installed assembly preload hooks to search for mscorlib.dll before
falling back to the default lookup strategy.

Fix 'thread may have been prematurely finalized' warnings when a GC happens during thread attach in sgen.

Rework TCP listening model, and fix AcceptTcpClient() to not drop timed out requests that actually steals next requests in the air.

* System.ServiceModel.Channels/HttpRequestChannel.cs: For Moonlight use
the WebResponse.SupportsHeaders before accessing the Headers collection.
This is needed because (the default) browser stack does not expose the
headers from its responses. Fix bug #642193

Turn Is*LockHeld properties into thread-specific values in ReaderWriterLockSlim. Add corresponding unit tests.

The patch removes a small race condition where a boolean flag is set after acquiring a lock to
indicate to code executing in the finally {} block that it should release the lock. The boolean
variable is now removed and the lock is released unconditionally. It carries a potential to
throw an exception when the lock is not held, but it's better than to fail to release it and
lead the application to a deadlock.

* System/Uri.cs: Avoid the culture-specific String.EndsWith when
reducing an URI

* System.Net.Policy/CrossDomainPolicyManager.cs: Use same socket family
as the endpoint when retrieving the policy. Also do not try to create a
policy out of an empty stream (avoid misleading exceptions in logs)

* System.Net.Sockets/SocketAsyncEventArgs.cs: Set the Socket
RemoteEndPoint to our RemoteEndPoint on Connect operation.
* System.Net.Sockets/Socket_2_1.cs: Return the 'candidate' EndPoint
provided by SocketAsyncEventArgs in ConnectAsync (intead of null)
until the connection is completed.

* NamedServiceModelExtensionCollectionElement.cs: minimum length of the Name property value is 0 for 4.0
* ServiceBehaviorElementCollection.cs: added an override of BaseAdd which makes sure that the element being
  added has its Name set to String.Empty if the element's name is null
* ServiceHostBase.cs: support for simplified behavior configuration. Refactored behavior addition code to a
  separate method. Check whether behavior is not in the collection before adding it.

	* method-to-ir.c (mono_method_to_ir): Check for null
	on delegate construction so closed-on-null is not allowed
	when using the delegate .ctor.

	If the delegate been constructed is open-on-target then
	the null check must not be applied as the IL pattern is:

	ldnull
	ldftn void Bla::Foo(int)
	newobj Bar (object, native int) // delegate void Bar(Bla,int)

	* icall.c (ves_icall_get_enum_info): All instance fields
	should be ignored here.

	Fixes #604218

	* Form.cs: When setting DialogResult call RaiseCloseEvents
	instead of directly setting 'closing', since we need to have our
	FormClosing event invoked *before* the form dissapears, so the
	user can properly cancel the close operation if desired.
	Fixes #631810.

	* X11Keyboard.cs: Manually handle the conversion of the string
	returned by XLookupString, just as we were already doing for XIM
	support - using StringBuilder directly was somehow returning a
	corrupt buffer from time to time.
	Fixes #639939.

[wcf] System.ServiceModel.Configuration.CustomBindignCollectionElement.GetDefault returns an instance of CustomBinding

	SocketAsyncEventArgs.LastOperation is set when the operation is
	invoked.
	Reset the error status before each new *Async() call.