'RELENG_6_0_0_RELEASE'.

This commit was manufactured to restore the state of the 6.0-RELEASE image.

compiling on IRIX and Solaris.  Remove the "archive_check_magic" macro
that existed only to provide __func__ to the underlying __archive_check_magic
function.

Thanks to: Darin Broady
MFC after: 14 days

This change also pointed out one API deficiency: the
archive_read_data_into_XXX functions were originally defined to return
the total bytes read.  This is, of course, ambiguous when dealing with
non-contiguous files.  Change it to just return a status value.

 * New read_data_block is both sparse-file aware and uses zero-copy semantics
 * Push read_data_block down into specific formats (opens door to
   various encoded entry bodies, such as zip or gtar -S)
 * Reimplement read_data, read_data_skip, read_data_into_fd in terms
   of new read_data_block.
 * Update documentation
It's unfortunate that I couldn't just call the new interface
archive_read_data, but didn't want to upset the API that much.

during lengthy extract operations.

  try to set ACLs even if fflag restore fails, first cut at reading
  Solaris tar ACLs

Code improvement: merge gnu tar read support into main tar reader;
  this eliminates a lot of duplicate code and generalizes the tar
  reader to handle formats with GNU-like extensions.

Style: Makefile cleanup, eliminate 'dmalloc' references, remove 'tartype'
  from archive_entry (this makes archive_entry more format-agnostic)

Thanks to: David Magda for providing Solaris tar test files

* Disabled shared-library building, as some API breakage is
  still likely.  (I didn't realize it was turned on by default.)  If
  you have an existing /usr/lib/libarchive.so.2, I recommend deleting it.
* Pax interchange format now correctly stores and reads UTF8
  for extended attributes.  In particular, pax format can portably
  handle arbitrarily long pathnames containing arbitrary characters.
* Library compiles cleanly at -O2, -O3, and WARNS=6 on all
  FreeBSD-CURRENT platforms.
* Minor portability improvements inspired by Juergen Lock
  and Greg Lewis.  (Less reliance on stdint.h, isolating of
  various portability-challenged constructs.)
* archive_entry transparently converts multi-byte <-> wide character
  strings, allowing clients and format handlers to deal with either
  one, as appropriate.
* Support for reading 'L' and 'K' entries in standard tar archives
  for star compatibility.
* Recognize (but don't yet handle) ACL entries from Solaris tar.
* Pushed format-specific data for format readers down into
  format-specific storage and out of library-global storage.  This
  should make it easier to maintain individual formats without mucking
  with the core library management.
* Documentation updates to track the above changes.
* Updates to tar.5 to correct a few mistakes and add some additional
  information about GNU tar and Solaris tar formats.

Notes:
* The basic 'tar' reader is getting more general; there's not much
  point in keeping the 'gnutar' reader separate.  Merging the two
  would lose a bunch of duplicate code.
* The libc ACL support is looking increasingly inadequate for my needs
  here.  I might need to assemble some fairly significant code for
  parsing and building ACLs. <sigh>

Portability: Thanks to Juergen Lock, libarchive now compiles cleanly
on Linux.  Along the way, I cleaned up a lot of error return codes and
reorganized some code to simplify conditional compilation of certain
sections.

Bug fixes:
  * pax format now actually stores filenames that are 101-154
    characters long.
  * pax format now allows newline characters in extended attributes
    (this fixes a long-standing bug in ACL handling)
  * mtime/atime are now restored for directories
  * directory list is now sorted prior to fix-up to permit
    correct restore of non-writable dir heirarchies

What it is:
   A library for reading and writing various streaming archive
   formats, especially tar and cpio.  Being a library, it should
   be easy to incorporate into pkg_* tools, sysinstall, and any
   other place that needs to read or write such archives.

Features:
  * Full automatic detection of both compression and archive format.
  * Extensible internal architecture to make it easy to add new formats.
  * Support for "pax interchange format," a new POSIX-standard tar format
    that eliminates essentially all of the restrictions of historic formats.
  * BSD license

Thanks to: jkh for pushing me to start this work, gordon for
  encouraging me to commit it, bde for answering endless style
  questions, and many others for feedback and encouragement.

Status: Pretty good overall, though there are still a few rough edges and
  the library could always use more testing.  Feedback eagerly solicited.