MFC r316456,352732:
Sync libarchive with vendor.

MFC r316456:
Vendor changes (FreeBSD-related):
Report which extended attributes could not be restored
Update archive_read_disk.3 and archive_write_disk.3 manual pages
Plug memory leaks in xattr tests.

MFC r352732:
Relevant vendor changes:
Issue #1237: Fix integer overflow in archive_read_support_filter_lz4.c
PR #1249: Correct some typographical and grammatical errors.
PR #1250: Minor corrections to the formatting of manual pages

MFC r299529,r299540,r299576,r299896:

r299529,r299540:
Update libarchive to 3.2.0

New features:
- new bsdcat command-line utility
- LZ4 compression (in src only via external utility from ports)
- Warc format support
- 'Raw' format writer
- Zip: Support archives >4GB, entries >4GB
- Zip: Support encrypting and decrypting entries
- Zip: Support experimental streaming extension
- Identify encrypted entries in several formats
- New --clear-nochange-flags option to bsdtar tries to remove noschg and
similar flags before deleting files
- New --ignore-zeros option to bsdtar to handle concatenated tar archives
- Use multi-threaded LZMA decompression if liblzma supports it
- Expose version info for libraries used by libarchive

r299576,r299896:
Fix broken cpio behavior.

Relnotes: yes