This patch adds full lzip/lunzip support to busybox, including seamless
lz decompression (of tar.lz files, etc), but not including tar.lz
archive creation.

With all features enabled, this patch adds 12272 bytes to busybox on x86
(see busybox_objsizes.diff).

I think this patch follows all the guidelines of new-applet-HOWTO.txt.

It has to be applied to the corresponding busybox release like this:

  cd busybox-VERSION
  patch -p1 < PATH/busybox-VERSION_lzip-N.patch
  chmod a+x testsuite/lunzip.tests testsuite/lzip.tests


This patch adds the following files:
  archival/libarchive/decompress_lunzip.c
  archival/libarchive/get_header_tar_lz.c
  archival/libarchive/lzip.h
  archival/lzip.c
  testsuite/lunzip.tests
  testsuite/lzip.tests

And modifies the following files:
  archival/Config.src
  archival/Kbuild.src
  archival/bbunzip.c
  archival/libarchive/Kbuild.src
  archival/libarchive/filter_accept_list_reassign.c
  archival/libarchive/open_transformer.c
  archival/tar.c
  configs/TEST_nommu_defconfig
  configs/TEST_noprintf_defconfig
  configs/TEST_rh9_defconfig
  configs/android2_defconfig
  configs/android_defconfig
  configs/android_ndk_defconfig
  configs/cygwin_defconfig
  configs/freebsd_defconfig
  include/applets.src.h
  include/bb_archive.h
  include/libbb.h
  miscutils/man.c
  testsuite/bunzip2.tests
  testsuite/tar.tests


Description of the new files:
  archival/libarchive/decompress_lunzip.c
    Lunzip implementation. Defines the function 'unpack_lz_stream'.
  archival/libarchive/get_header_tar_lz.c
    Defines the function 'get_header_tar_lz'.
  archival/libarchive/lzip.h
    Common definitions for lzip and lunzip.
  archival/lzip.c
    Lzip implementation. Defines the function 'lzip_main'.
  testsuite/lunzip.tests
    Executes 'bunzip2.tests' with ext=lz.
  testsuite/lzip.tests
    Tests lzip compression using the new method (see testsuite/TODO).

Description of the changes to the existing files:
  archival/Config.src
    Added FEATURE_SEAMLESS_LZ, LUNZIP and LZIP.
    Added FEATURE_SEAMLESS_LZ to the definition of FEATURE_TAR_AUTODETECT.
  archival/Kbuild.src
    Added lib-$(CONFIG_LZIP) and lib-$(CONFIG_LUNZIP).
  archival/bbunzip.c
    Modified 'make_new_name_generic' So that it also replaces tlz --> tar.
    This change works for all extensions except Z (tbz2,tlz,tlzma,txz),
    making the behaviour of all decompressors consistent with gzip and
    with the 'real' decompressors.
    Added 'lunzip_main'.
  archival/libarchive/Kbuild.src
    Addded lib-$(CONFIG_LUNZIP) and lib-$(CONFIG_FEATURE_SEAMLESS_LZ).
  archival/libarchive/filter_accept_list_reassign.c
    Added lzip support to dpkg.
  archival/libarchive/open_transformer.c
    Added lzip magic support to 'setup_unzip_on_fd'.
  archival/tar.c
    Added option '-y, --lzip' to tar for lzip decompression (conditioned
    to IF_FEATURE_SEAMLESS_LZ).
  configs/TEST_nommu_defconfig
  configs/TEST_noprintf_defconfig
  configs/TEST_rh9_defconfig
  configs/android2_defconfig
  configs/android_defconfig
  configs/android_ndk_defconfig
  configs/cygwin_defconfig
  configs/freebsd_defconfig
    Added suitable definitions of CONFIG_FEATURE_SEAMLESS_LZ, CONFIG_LUNZIP
    and CONFIG_LZIP to all *_defconfig files.
  include/applets.src.h
    Added
    IF_LUNZIP(APPLET(lunzip, BB_DIR_USR_BIN, BB_SUID_DROP))
    IF_LZIP(APPLET(lzip, BB_DIR_USR_BIN, BB_SUID_DROP))
  include/bb_archive.h
    Defined LZIP_MAGIC1 and LZIP_MAGIC2.
    Added prototypes for functions 'get_header_tar_lz' and 'unpack_lz_stream'.
  include/libbb.h
    Added ENABLE_FEATURE_SEAMLESS_LZ to the definition of
    SEAMLESS_COMPRESSION.
    Added prototype for function 'lunzip_main'.
  miscutils/man.c
    Added support for lzipped manpages to 'show_manpage'.
  testsuite/bunzip2.tests
    Use it to test lunzip (in addition to gunzip and bunzip2).
    Added new test 'replace .t$ext --> .tar' (for tgz/tbz2/tlz).
  testsuite/tar.tests
    Added new test 'tar extract tlz'.