Commit Briefs
portable: handle sys/tree.h
Unfortunately, MacOS doesn't provide sys/tree.h -- so the compat check for this must happen portably.
portable: remove sha1.h include
This is searched for portably.
move code for reading Git's config file into new file read_gitconfig_privsep.c
The end goal here is to remove the dependency of repository.c on privsep.c during compilation.