Use the documented NDR_PROC_HEADER_EXTS structure instead of the
current NDR_PROC_EXTENSIONS structure currently in ndr_stubless.c.

Store the return value on the stack for stubs, as MIDL reserves space
for it and gives us a stack offset. This fixes calling methods with
thunks that assume that the return value will be stored on the stack.

Correctly fill in StackTop for stubless clients/servers so that
conformance for top-level parameters works.

Fix the MSVC version of call_server_func to pop the registers in the
same order they were pushed.

Based on a patch by Mike McCormack.

in an active process, instead of sending a SIGTRAP.

The HDN_ITEMCHANGING notify should have the new data instead of the
old one.  Both HDN_ITEMCHANGING and HDN_ITEMCHANGED now have the text
field if it changed.

Based on some documentation by Rob Shearman.

- Find menus by ID: Proper fallback to popup menus.
- Use the menu ID, not the handle for the fallback.
- Save the fallback menu's position.