Add compatibility shims and basic Mac OS X build fixes.
Initial adoption of OS X compatibility shims.
Initial adoption of OS X compatibility shims.
Include fstatat() shim.
Use compatibility shims for humanize_number()
Use compatibility shims for strtonum().
Remove unnecessary reference to AT_FDCWD.
Additional OS X portability fixes.
Add OpenSSH's closefrom() replacement implementation.
Enable use of closefrom() and eaccess() shims.
Add faccessat() and freadlinkat() compatibility shims.
Add FreeBSD's endian utils.
Merge branch 'master' into osx/main
Use bsd_compat.h to provide faccessat().
Replace incorrect to builddir with srcdir.
Fix portable build of test suite.
Disable building of elf-specific code on Mach-O systems.

The only Mach-O system supported is Darwin.
Add a stub Mach-O implementation.
Add machista library from MacPorts trunk r129895.

This provides Mach-O parsing support necessary for the implementation of
pkg_macho.c
Add parsing of Mach-O files.