[sockets] Implement DuplicateAndClose and Socket (SocketInformation) constructor for in-process socket passing (AppDomains)

Validation is enabled early in the pipeline during request. ValidationUtility makes sure that validation is indeed enabled and
replaces the default form and query string collections with a lazy version which will validate values only when an existing key
is found and requested.

This method is not used by Mono internally but is called by MVC v3.

[asp.net] Added internal property InputValidationEnabled to report whether the user enabled validation for current request.

	* sgen-gc.c (finish_gray_stack): We must clear
	weak refs that don't track resurrection before
	processing finalizable objects otherwise we'll
	copy/mark them and the weak ref won't be cleared
	until after finalization.

	Fixes #657408

This is the same as 6c02c151, but only for ia64, to avoid destabilizing the
branch.

	* verify.c (is_valid_generic_instantiation): Don't
	check if any argument is broken during constraint check
	as an instance should be valid, but not realizable, even
	if it has broken arguments.

	Fixes one of the issues with #664612

	Patch by Thad Thompson <TThompson@nucsafe.com>