Resolve conflicts in favor of the upstream side where possible.
Resolve a logical conflict in archive_windows.h where the upstream
port to Watcom was done slightly differently from ours.
Port upstream commit 6cf33c93 (Issue 320: Rewrite (again) to avoid
the left shift that CLang dislikes so much, 2013-12-07) into CMake.
Inspired-by: Tim Kientzle <kientzle@freebsd.org>
Port upstream commit 533e8fda (Rework the sign-extension to avoid
left-shift of an explicit negative number, 2013-06-29) into CMake.
Inspired-by: Tim Kientzle <kientzle@freebsd.org>
This allows for a built in bzip and zip capability, so external tools
will not be needed for these packagers. The cmake -E tar xf should be
able to handle all compression types now as well.