stream_dvd, cache: hack seeking with --cache + dvd:// back into working

This was broken at some unknown point (even before the recent cache
changes). There are several problems:
- stream_dvd returning a random stream position, confusing the cache
  layer (cached data and stream data lost their 1:1 corrospondence by
  position)
- this also confused the mechanism added with commit a9671524, which
  basically triggered random seeking (although this was not the only
  problem)
- demux_lavf requesting seeks in the stream layer, which resulted in
  seeks in the cache or the real stream

Fix this by completely removing byte-based seeking from stream_dvd. This
already works fine for stream_dvdnav and stream_bluray. Now all these
streams do time-based seeks, and pretend to be infinite streams of data,
and the rest of the player simply doesn't care about the stream byte
positions.

0 files changed, 0 insertions, 0 deletions