avconv: make -shortest work with streamcopy

CC: libav-stable@libav.org
(cherry picked from commit 48e50921337984ba4ec2c1cafe45d43787f84498)
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Merge commit '6672f672d98cf4887e13321b6f67682cfd1273b4' into release/2.2

* commit '6672f672d98cf4887e13321b6f67682cfd1273b4':
  avconv: make -shortest work with streamcopy

Conflicts:
	ffmpeg.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Show duration for large asf files as written in the file header.

Fixes ticket #3428.
(cherry picked from commit e3fd263f0b73e4425192d6dd1ab18027ecaa35db)
avutil/lzo: Fix integer overflow

Embargoed-till: 2014-06-27 requested by researcher, but embargo broken by libav today (git and mailing list)

Fixes: LMS-2014-06-16-4
Found-by: "Don A. Bailey" <donb@securitymouse.com>
See: ccda51b14c0fcae2fad73a24872dce75a7964996
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit d6af26c55c1ea30f85a7d9edbc373f53be1743ee)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avutil/lzo: add asserts to be double sure against overflows

These asserts cannot fail since d6af26c55c1ea30f85a7d9edbc373f53be1743ee

Based-on: ccda51b14c0fcae2fad73a24872dce75a7964996
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit cf2b7c01f81c1fb3283a1390c0ca9a2f81f4f4a8)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>