ape: fix seeking (with ffplay)

[ami_stuff]

seeking doesn't work too good and takes too long time compared for example to foobar2000

​http://streams.videolan.org/issues/6348/Goldwave-MAClib.ape

C:\>ffmpeg -i Goldwave-MAClib.ape
ffmpeg version N-46755-ge70144c Copyright (c) 2000-2012 the FFmpeg developers
  built on Nov 15 2012 02:38:20 with gcc 4.5.0 (GCC) 20100414 (Fedora MinGW 4.5.
0-1.fc14)
  configuration: --prefix=/var/www/users/research/ffmpeg/snapshots/build --arch=
x86 --target-os=mingw32 --cross-prefix=i686-pc-mingw32- --cc='ccache i686-pc-min
gw32-gcc' --enable-w32threads --enable-memalign-hack --enable-runtime-cpudetect
--enable-cross-compile --enable-static --disable-shared --extra-libs='-lws2_32 -
lwinmm -lpthread' --extra-cflags='--static -I/var/www/users/research/ffmpeg/snap
shots/build/include' --extra-ldflags='-static -L/var/www/users/research/ffmpeg/s
napshots/build/lib' --enable-bzlib --enable-zlib --enable-gpl --enable-version3
--enable-nonfree --enable-libx264 --enable-libspeex --enable-libtheora --enable-
libvorbis --enable-libfaac --enable-libxvid --enable-libopencore-amrnb --enable-
libopencore-amrwb --enable-libmp3lame --enable-libvpx --disable-decoder=libvpx
  libavutil      52.  6.100 / 52.  6.100
  libavcodec     54. 71.100 / 54. 71.100
  libavformat    54. 36.100 / 54. 36.100
  libavdevice    54.  3.100 / 54.  3.100
  libavfilter     3. 23.100 /  3. 23.100
  libswscale      2.  1.102 /  2.  1.102
  libswresample   0. 16.100 /  0. 16.100
  libpostproc    52.  1.100 / 52.  1.100
Input #0, ape, from 'Goldwave-MAClib.ape':
  Metadata:
    Track           : 1
    Year            : 1983
    Genre           : Rock
    Artist          : YES
    Album           : 90125
    Title           : Owner of a Lonely Heart
  Duration: 00:00:29.32, start: 0.000000, bitrate: 837 kb/s
    Stream #0:0: Audio: ape (APE  / 0x20455041), 44100 Hz, stereo, s16p
At least one output file must be specified

[Carl Eugen Hoyos]

Pressing "down" after 14 seconds let the player continue to play until ~20:00 seconds before seeking.

[Marton Balint]

Fixed in latest git master.