Cause MenuDeactivate event to be delivered when appropriate

This is achieved by moving the FireMenuDeactivate call to
MenuStrip.Dismiss and causing it to be called in a couple of places
where it ought to be.
X11: improve handling of WS_EX_TOPMOST

Currently, WS_EX_TOPMOST is handled by making the window transient-for
the root window.  I was unable to find any documentation that indicated
that this would have the desired effect.  Instead, use SetTopmost to
set _NET_WM_STATE to _NET_WM_STATE_ABOVE, per EWMH.

Also, use XMapRaised to raise topmost windows to the top of the stack
when mapped, as a last ditch effort to support window managers that
do not respect _NET_WM_STATE, such as xmonad.

This fixes an issue I encountered when running a winforms application
in xmonad, whereby drop down menus would fail to re-open if windows
had been re-arranged after the menu was first opened (in reality,
the menu was hiding behind the form).
Ignore the gdiplus dllmap on Windows.
Fix Bug 4811, xbuild should find xml documentation
[System] Don't overwrite custom Connection header on HttpWebRequest
[System] Add crude (for now) socket stealing of an HttpWebRequest.

HttpWebRequest is a very tricky piece of code when it comes to its socket, this patch is more like a hack to get something working out of it but it's definitely not the best option.
[System] Implement a first pass of ClientWebSocket.
Fixed xamarin bug #13708: routing constraints should be trated as 'convertible to string' in order to be compat with MS.NET
Annonymous method storey inside async storey has to capture this directly when the storey does not have any parents. Fixes #14126
Fix yet another DISABLE_JIT bug in wrapper generation. Fixes #14194.
We have g_getenv for portability reasons, so let's use it.
SRE.ParameterBuilder cannot be exposed in FULL_AOT_RUNTIME
Some enhancements and additions to DataAnnotations, incluiding implemented of a few missing pieces of Sys.ComponentModel.DataAnnotations v4.5, like:
	- CompareAttribute
	- CreditCardAttribute
	- EmailAddressAttribute
	- FileExtensionsAttribute
	- PhoneAttribute
	- Implemented  IsValid() methods of Min/MaxLengthAttribute.
	- Fixed all existing Validation attributes so they take into account current's locale when composing ErrorMessage.
Set correct author on test files.
Add test for #12745
Reverted string.Format(CultureInfo.CurrentCulture, ..) change.
Merge pull request #740 from pruiz/dataannotations-enhancements

Some enhancements and additions to DataAnnotations, incluiding implementation of a few missing pieces of Sys.ComponentModel.DataAnnotations v4.5, like:
cleaned console logs in MakeExpression function

Cleaned verbose logs leftovers (probably debug ones) that are currently printed on every compiling that involves dynamic objects...
cleaned console logs in MakeExpression function

Cleaned verbose logs leftovers (probably debug ones) that are currently printed on every compiling that involves dynamic objects...
Merge pull request #741 from marcominetti/master

Clean verbose (debug) logs in mcs for MakeExpression function call