* libc/stdio/fvwrite.h: change type of uio_resid from int to size_t to
	fix fwrite() of > 2GByte buffers.
	* devices.in (dev_cygdrive_storage): Revert mapping to \Device\Null.
	(dev_storage): Ditto for /dev.
	* devices.cc: Regenerate.
	* fhandler.cc (fhandler_base::open_null): New method to open a fake
	\Device\Null handler.
	(fhandler_base::open): Fix formatting.  Change O_ACCMODE test to a
	switch statement.  Simplify a test which still tested for a now unused
	create_disposition.
	* fhandler.h (fhandler_base::open_null): Declare.
	(fhandler_netdrive::close): Declare.
	* fhandler_dev.cc (fhandler_dev::open): Open fake \Device\Null handle
	by just calling new open_null method.
	* fhandler_disk_file.cc (fhandler_cygdrive::open): Ditto.
	* fhandler_netdrive.cc (fhandler_netdrive::open): Call open_null
	rather than setting nohandle.
	(fhandler_netdrive::close): New method.
	* fhandler_registry.cc (fetch_hkey): Fix token in RegOpenUserClassesRoot
	call.  Create valid key for HKEY_CURRENT_CONFIG by mapping to real key
	HKEY_LOCAL_MACHINE\System\CurrentControlSet\Hardware Profiles\Current.
	(fhandler_registry::open): Set nohandle only when using pseudo registry
	handle.
	* fhandler_virtual.cc (fhandler_virtual::opendir): Call open rather
	than just setting nohandle here.
	* fhandler_virtual::fstatvfs): Set ST_RDONLY fs flag.
	* globals.cc (ro_u_null): New readonly UNICODE_STRING for \Device\Null.
	* path.h (path_conv::set_path): Revert previous change caring for
	wide_path.