The usage of timsort instead of std::sort at this point is twofold. First,
it's faster in our case where the array is already sorted in many cases
(remember this is called at least once a frame). And it's not just a bit
faster either but a lot. I have measured a factor of 7 on my system.
Second, in our Windows autobuilds there is a crash within std::sort which is
very hard to debug because it's hardly reproducible with anything other than
the autobuilds (I tried hard). If the crash goes away with timsort then
great, if not then maybe it's easier to debug since the code is in our tree.
Some build systems, particularly MSVC, don't ship with an implementation
of getopt or getopt_long in their standard library. This patch adds a BSD
licensed implementation, to be used in case there is no system provided
one.
Nicolas Hake