A couple of fixes around XamlSchemaContext.GetXamlType(XamlTypeName) and get XamlXmlReader pass with unknown type names.

	The EndPoint argument in Begin/EndSendTo cannot be null.

	Read/Write were creating one callback instance per call. Now we keep
	the same delegate around for all the calls.

	We were ignore possible errors when reading after a socket has been
	accepted.

	When possible, schedule the user callback from unmanaged code. We pass
	it from the IO pool to the regular pool after our internal callback is
	finished.

Check the debugger_thread_exited condition in a loop to guard against spurious wakeups. Fixes #642780.

Work around Android's pthread/kernel_id/fork bug to fix mono multithreading and GC_stop_world in processes that have been forked.

error_msg is null when passed into this function from a few places, so
lets not do a null deref here.

Fix a deadlock introduced by 5c2e3bf7 by using a separate low level lock to procect access to the file_share_hash hash table. Fixes #642985.

[wcf] serialization member namespace was wrong when root namesp ace is given. Fixed possible infinite loop during DefaultTypeMap initialization.

MS Basic/Contract/Data/POCO sample got working fine.

If ReleaseResources or Flush (true) were called, a flag is set that causes
any subsequent Flush () calls to fail with an exception.
At the same time, ReleaseResources does not destroy the output stream completely -
it has to remain around to match .NET behavior.

This reverts commit a4ed8be6 since what we
do in ReleaseResources is not what .NET does - a better fix will follow.

	The callbacks need to be invoked in different threads to avoid clogging
	the IO pool.

	Fixes bug #639656.

Disable the freeing of monitors again, it still crashes with sgen when running tests/async_read.exe.

* System.Net.Sockets/Socket_2_1.cs: Fix, by explicitely throwing an NRE,
the checks in [Receive|Send]Async methods - otherwise an exception would
occur later, on another thread and close the socket (leading to other,
unexpected, exceptions)

* Test/System.Net.Sockets/SocketTest.cs: Add parameter validation test
cases for both ReceiveAsync and SendAsync

* System.Net.Sockets/SocketAsyncEventArgs.cs: Move policy restriction
and elevated trust check outside of loop since its value won't change
based on the ipaddress

* System.Net.Sockets/Socket_2_1.cs: Do not #id-def out [Receive|Send]
Generic from moonlight build

	If creating the xdb.il file fails, disable the mono support for
	debugging in gdb. Managed symbol names won't be displayed in stack
	traces.

	Fixes bug #642625.