Initial Visual C++ / C89 version
timsort_arg version added

Added a version of timsort (timsort_arg) where the comparison callback
takes an additional parameter which can be used for application-defined
context (similar to qsort_r)
Change order of comparator for timsort_arg

BSD qsort_r takes the context as the first param to the comparator
function. Changed timsort_arg to match that
Changed timsort_arg to timsort_r to match BSD
Fixed prototype.
Switch timsort_r from Windows to BSD arg order
Add separate C file for timsort_r
Use _alloca for temp variables on Windows (untested)
Whitespace
Remove leading underscore from #define _TIMSORT_H
Add Apache-2.0 License
Update README, add AUTHORS