include: Add function declarations for CoAllowSetForegroundWindow and CoRegisterChannelHook to objbase.h.

wined3d: Cleanup & merge pshader_get_input_register_swizzle() and vshader_program_add_input_param_swizzle().

As spotted by Christoph Bumiller, these branches are now never
reached. Also, at least in the case of WINED3DSIO_TEXM3x3SPEC and
WINED3DSIO_TEXM3x3VSPEC the old code was not quite correct, since we
can lookup rather than guess the texture type these days.

When querying a listview subitem for the user param, the main item's
user param is returned. Also, when a subitem is custom-drawn, the main
item's user param is passed along.