log: Unbreak no-tty support on 256color terminals
probe: Bump the score for mime type matching

It should be more trustworthy than extension matching.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
avconv: Use only audio and video to guess discontinuities

Data and subtitle streams might cause false positive.
configure: Assume a standard-compliant default libc

Non-standard compliant libc should be supported on a per-case basis
anyway.
hwaccel: Call ->get_format again if hwaccel init fails

This allows the application to fall back on another hwaccel or,
more likely, software decoding.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
h264: Always invoke the get_format() callback

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
mpeg12: Always invoke the get_format() callback

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>