Bug 15574. XML deserialization recursion: add array type to known_types?

One way to prevent https://bugzilla.xamarin.com/show_bug.cgi?id=15574 is to add the problematic array type to the `known_types`.

On the other hand, this might not be the intended use of `known_types`. In that case, perhaps a better fix would be to guard against recursion in the `foreach` loop:

	if (t != type)
		RegisterTypeAsKnown (t);
Bug 15572. Lookup KnownTypeCollection element types in MSSimpleNamespace

This patch prevents the problem in https://bugzilla.xamarin.com/show_bug.cgi?id=15572. This change allows the DataContractSerializer to deserialize DataMembers that use an array KnownType, at least for the test case in the bug report.
SqlBulkCopy Implementation

This are the code changes to get the SqlBulkCopy procedure working on
mono.
Support for DispIdAttribute in GetIdsOfNames

License: This patch is under the MIT/X11 license.
Convert blocking operations in HttpWebRequest and SslClientStream to non-blocking operations. This fixes #15451.

More details:
  * HttpWebRequest now writes the HTTP request headers asynchronously. This will avoid blocking a thread pool thread until the headers are written.
  * SslClientStream was doing the TLS negotiations in a blocking manner. Converted the negotiation method to an async state machine where all operations are done asynchronously.
  * The test case identified in #15451 now completes quickly with less than 15 threads created, vs. 100s of threads used before this fix.

Future work if needed:
  * I did not convert SslServerStream but the same pattern could be used here.
  * SendAlert is still blocking. I thought it was not worth converting it to non-blocking.
Fixes Xamarin Bug 16742:  XmlConvert.ToDateTime(string, XmlDateTimeSerializationMode) throws index out of bounds exception

Fix for bug + added tests for method
XmlConvert.ToDateTime(string, XmlDateTimeSerializationMode)
Additional tests for Xamarin Bug 16742 + style enhancements
Cleaned up the using statements in DateTime tests
Prevent exception in finalization of Form class

If initialization of the Form class or one of its base classes fails, possibly because X11 is not available and the constructor of the parent Control class throws an exception, the owned_forms member is not initialized. This results in a NullReferenceException during initialization, if the error that occurs during construction is handled.

Stack traces:
Unhandled Exception:
System.TypeInitializationException: An exception was thrown by the type initializer for System.Windows.Forms.WindowsFormsSynchronizationContext ---> System.TypeInitializationException: An exception was thrown by the type initializer for System.Windows.Forms.XplatUI ---> System.ArgumentNullException: Could not open display (X-Server required. Check you DISPLAY environment variable)
Parameter name: Display
  at System.Windows.Forms.XplatUIX11.SetDisplay (IntPtr display_handle) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUIX11..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUIX11.GetInstance () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUI..cctor () [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Windows.Forms.Theme.get_MenuAccessKeysUnderlined () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.SystemInformation.get_MenuAccessKeysUnderlined () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Control..ctor () [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor ()
  at System.Windows.Forms.WindowsFormsSynchronizationContext..cctor () [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Windows.Forms.Control..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.ScrollableControl..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.ContainerControl..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Form..ctor () [0x00000] in <filename unknown>:0
  at AutoCRCheck.frmOptions..ctor () [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) AutoCRCheck.frmOptions:.ctor ()
  at AutoCRCheck.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: An exception was thrown by the type initializer for System.Windows.Forms.WindowsFormsSynchronizationContext ---> System.TypeInitializationException: An exception was thrown by the type initializer for System.Windows.Forms.XplatUI ---> System.ArgumentNullException: Could not open display (X-Server required. Check you DISPLAY environment variable)
Parameter name: Display
  at System.Windows.Forms.XplatUIX11.SetDisplay (IntPtr display_handle) [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUIX11..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUIX11.GetInstance () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.XplatUI..cctor () [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Windows.Forms.Theme.get_MenuAccessKeysUnderlined () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.SystemInformation.get_MenuAccessKeysUnderlined () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Control..ctor () [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) System.Windows.Forms.Control:.ctor ()
  at System.Windows.Forms.WindowsFormsSynchronizationContext..cctor () [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at System.Windows.Forms.Control..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.ScrollableControl..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.ContainerControl..ctor () [0x00000] in <filename unknown>:0
  at System.Windows.Forms.Form..ctor () [0x00000] in <filename unknown>:0
  at AutoCRCheck.frmOptions..ctor () [0x00000] in <filename unknown>:0
  at (wrapper remoting-invoke-with-check) AutoCRCheck.frmOptions:.ctor ()
  at AutoCRCheck.Program.Main (System.String[] args) [0x00000] in <filename unknown>:0

---------------------------------------------------------
Handling the previous exception results in the following exception:

System.NullReferenceException: Object reference not set to an instance of an object
  at System.Windows.Forms.Form.Dispose (Boolean disposing) [0x00000] in <filename unknown>:0
  at AutoCRCheck.frmOptions.Dispose (Boolean disposing) [0x00000] in <filename unknown>:0
  at System.ComponentModel.Component.Finalize () [0x00000] in <filename unknown>:0
Implemented overloaded versions of Parse and TryParse functions for BigInteger.

Implementation is heavily inspired by Int32.
Added unit tests for the new functions.
Merge branch 'BigIntegerParse'
[corlib] Default comparer uses IComparable interface only
[corlib] Fixes formatting of nested tuples
[corlib] Make primitive types smaller than int compare result compatible
Merge pull request #829 from symform/httpwebreq-async-ssl

Convert blocking operations in HttpWebRequest and SslClientStream to non-blocking
[numerics] Fix type in Cosh
[jit] Fix a regression introduced by b3f36681c72a6900cd5e9df9b593d555b351669f.
Merge remote-tracking branch 'upstream/master'
Cleanup and better comment.
Implemented DaysInYearBeforeMinSupportedYear for all Calendars that should have it in .Net 4.5