manpage: improve --input-cursor description
options: merge ---sub-auto-match with --sub-auto

There's no reason why these should be separate.
vdpau: deduplicate video surface upload code

This was a minor code duplication between vf_vdpaupp.c and vo_vdpau.c.

(In theory, we could always require using vf_vdpaupp with vo_vdpau, but
I think it's better if vo_vdpau can work standalone.)
vf_vdpaupp: make code clarity improvements

This shouldn't change anything functionally, except that it buffers 1
frame less in the first-field deinterlacing mode.