Merge from vendor branch KIENTZLE:

Merge from vendor branch KIENTZLE:
Import libarchive 2.8.0:
- Infrastructure:
  - Allow command line tools as fallback for missing compression
    libraries. If compiled without gzip for example, gunzip will
    be used automatically.
  - Improved support for a number of platforms like high-resolution
    timestamps and Extended Attributes on various Unix systems
  - New convience interface for creating archives based on disk content,
    complement of the archive_write_disk interface.
- Frontends:
  - bsdcpio ready for public consumption
  - hand-written date parser replaces the yacc code
- Filter system:
  - Simplified read filter chains
  - Option support for filters
  - LZMA, XZ, uudecode handled
- Format support:
  - Write support for mtree files based on file system or archive
    content
  - Basic read support for Joliet
  - Write support for zip files
  - Write support for shar archives, both text-only and binary-safe