Fixes encoding very large pictures.

Thanks to Костя for providing the formula.

CC: libav-stable@libav.org

Also set CODEC_CAP_DELAY to indicate that decoder may still have some
undecoded data left in internal buffer.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Kostya Shishkov <kostya.shishkov@gmail.com>

Break some of the longer sections into smaller sensible pieces;
make some option descriptions and option ordering more consistent.

The first frame pts must be saved until we have 8 frames since RoQ audio
requires 8 frames in the first packet.

Update FATE references due to encoder delay.

Encoder output is delayed by several frames, so we keep a queue of input
frame timing info to match up with corresponding output packets.

FATE reference updated due timestamp rounding because of resampling from
44100 Hz to 16000 Hz in avconv.

Update FATE references due to encoder delay.

This simplifies matching of timestamps between input frames and output
packets.

Fixes a memleak when using the -frames option with audio.

There is no reason for it to be public, it's only meant to be used
internally.

The caller can achieve the same effect (i.e. getting raw unparsed/mangled
packets) with av_read_frame() and AVFMT_FLAG_NOPARSE |
AVFMT_FLAG_NOFILLIN

Takes encoder delay into account by comparing first the coded page
duration with the calculated page duration. Handles last packet duration
if needed, also by comparing coded duration with calculated duration.
Also does better handling of timestamp generation for packets in the
first page for streamed ogg files where the start time is not
necessarily zero.

5 FATE test references updated due to using demuxer-generated timestamps that
are either not sample-accurate or are slightly off in the input file.

Also fixes stream duration calculation.