In order to parse a number from a string, the WebM DASH manifest muxer
would duplicate (via heap-allocation) the part of the string that
contains the number, then read the number via atoi() and then free the
duplicate again. This has been replaced by simply using strtoll() (which
in contrast to atoi() has defined behaviour when the number is not
representable).
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>