VFCAP_OSD was used to determine at runtime whether the VO supports OSD
rendering. This was mostly unused. vo_direct3d had an option to disable
OSD (was supposed to allow to force auto-insertion of vf_ass, but we
removed that anyway). vo_opengl_old could disable OSD rendering when a
very old OpenGL version was detected, and had an option to explicitly
disable it as well.
Remove VFCAP_OSD from everything (and some associated logic). Now the
vo_driver.draw_osd callback can be set to NULL to indicate missing OSD
support (important so that vo_null etc. don't single-step on OSD
redraw), and if OSD support depends on runtime support, the VO's
draw_osd should just do nothing if OSD is not available.
Also, do not access vo->want_redraw directly. Change the want_redraw
reset logic for this purpose, too. (Probably unneeded, vo_flip_page
resets it already.)
wm4
d511ef79a0