widl: Add support for generating code for out-only context handles by calling NdrContextHandleInitialize.

Server context handles are tracked from associations as their lifetime
is determined by the lifetime of the association.

Implement NdrServerContextMarshall and NdrServerContextNewMarshall on
top of NDRSContextMarshall2. Implement NdrContextHandleInitialize,
NdrServerContextUnmarshall and NdrServerContextNewUnmarshall on top of
NDSContextUnmarshall2.

write_embedded_types doesn't descend into all types contained by the
array or structure, so create a new function, type_has_pointers, for the
purpose of descending into all types and returning whether or not
pointers are present.

Has the lovely side effect of making Photoshop pressure + tilt work.

The XInput macros such as DeviceMotionNotify will correctly return an eventclass of 0
if the device id is 0.  Given that, we cannot use eventclass != 0 as a meaningful
test, and must instead use the returned type.

wintab32: Compute our physical device characteristics based on the first tablet device that looks like a stylus.

Otherwise, we may be computing based on a mouse or cursor, and then
come to incorrect values for our tilt and pressure settings.

Some microphones don't have a capture control, but a playback control
instead. So use the playback volume, but still register it as capture
volume.

valgrind: Made Wine compliant will latest Valgrind macros (the one removed from 3.3.0 and deprecated since 3.2.0).

These need to include their array part so use var->type instead of 
var->ref->type.