'RELENG_7_0_0_RELEASE'.

This commit was manufactured to restore the state of the 7.0-RELEASE image.

  * "compression_program" support uses an external program
  * Portability: no longer uses "struct stat" as a primary
    data interchange structure internally
  * Part of the above: refactor archive_entry to separate
    out copy_stat() and stat() functions
  * More complete tests for archive_entry
  * Finish archive_entry_clone()
  * Isolate major()/minor()/makedev() in archive_entry; remove
    these from everywhere else.
  * Bug fix: properly handle decompression look-ahead at end-of-data
  * Bug fixes to 'ar' support
  * Fix memory leak in ZIP reader
  * Portability: better timegm() emulation in iso9660 reader
  * New write_disk flags to suppress auto dir creation and not
    overwrite newer files (for future cpio front-end)
  * Simplify trailing-'/' fixup when writing tar and pax
  * Test enhancements:  fix various compiler warnings, improve
    portability, add lots of new tests.
  * Documentation: document new functions, first draft of
    libarchive_internals.3

MFC after: 14 days
Thanks to: Joerg Sonnenberger (compression_program)
Thanks to: Kai Wang (ar)
Thanks to: Colin Percival (many small fixes)
Thanks to: Many others who sent me various patches and problem reports.

Found by:	Coverity Prevent
Coverity ID:	CID 3132

  * libarchive_test program exercises many of the core features
  * Refactored old "read_extract" into new "archive_write_disk", which
    uses archive_write methods to put entries onto disk.  In particular,
    you can now use archive_write_disk to create objects on disk
    without having an archive available.
  * Pushed some security checks from bsdtar down into libarchive, where
    they can be better optimized.
  * Rearchitected the logic for creating objects on disk to reduce
    the number of system calls.  Several common cases now use a
    minimum number of system calls.
  * Virtualized some internal interfaces to provide a clearer separation
    of read and write handling and make it simpler to override key
    methods.
  * New "empty" format reader.
  * Corrected return types (this ABI breakage required the "2.0" version bump)
  * Many bug fixes.

a vanilla 2-clause BSD license, but somehow some confusing
extra verbage get copied from somewhere.

Also, update the copyright dates to 2007 for all of the files.

Prompted by: several questions about what those extra words really mean

internal format-specific functions return the same as the public
function, so that the public API layer doesn't have to guess the
correct return value.  This addresses an obscure problem that occurs
when someone tries to write more data than the size of the entry (as
indicated in the entry header).  In this case, the return value from
archive_write_data() was incorrect, reflecting the requested write
rather than the amount actually written.

MFC after: 15 days

  * Actually use the HAVE_<header>_H macros to conditionally include
    system headers.  They've been defined for a long time, but only
    used in a few places.  Now they're used pretty consistently
    throughout.
  * Fill in a lot of missing casts for conversions from void*.
    Although Standard C doesn't require this, some people have been
    trying to use C++ compilers with this code, and they do require it.

Bit-for-bit, the compiled object files are identical, except for
one assert() whose line number changed, so I'm pretty confident I
didn't break anything.  ;-)

write path.  In particular, this should
solve some problems people have seen with
bsdtar not exiting on various write errors.

Mostly, these were being used correctly even though a lot of
variables and function names were mis-named.

In the process, I found and fixed a couple of latent bugs and
added a guard against adding an archive to itself.