Bump bundled libarchive version to 3.5.2

- Update bunlded libarchive version used on Windows/Mac
- Enable requested zstd support while we are at it. Closes #211

dependencies/libarchive-3.5.2/contrib/README

@@ -0,0 +1,59 @@
+Many people have graciously sent me configuration
+files, small programs that use libarchive, and other
+useful and interesting tidbits.
+
+I do not support or use any of these; but if you can use them, enjoy!
+
+======================================================================
+
+From: Andre Stechert <andre@splunk.com>
+
+libarchive_autodetect-st_lib_archive.m4
+
+M4 macros for use with autoconf to detect whether a suitable
+version of libarchive is installed on this system.
+
+
+======================================================================
+
+libarchive.spec
+
+An RPM ".spec" file for building libarchive on most systems.
+This apparently was originally developed by a group at pld-linux.org.
+Several people have sent me different versions of this file.
+
+======================================================================
+
+From: Robert Meier <rm1023@dcx.com>
+
+libarchive.1aix53.spec
+
+As above, for use on AIX5.3.
+
+======================================================================
+
+psota-benchmark
+
+Some scripts used by Jan Psota in benchmarking
+various tar implementations.
+
+I've edited his results slightly to correctly reflect that
+bsdtar does not support a "compare" operation.
+
+======================================================================
+
+shar
+
+A simple shar program written on top of libarchive.
+
+======================================================================
+
+untar.c
+
+A very simple and very portable standalone program that can
+extract basic ustar archives.
+This does not use libarchive and so can be used to extract
+the libarchive distribution on any system that has a C compiler
+but does not have a tar program.
+
+======================================================================