Fix issue 356: properly skip a sparse file entry in a tar file.
Do not assume dir atime updates; not everyone does
Fix --one-file-system: do not descend, but do visit the root of a new filesystem
Simply finding a file name in mtree format to avoid redundant code.
Fix issue363:Unable to extract large 7z files.
Properly changing a variable type up to uint64_t.
Fix issue336:7zip can not be read when opened with archive_read_open_fd.
Implenent a seek callback in archive_read_open_fd by bringin the code
from archive_open_filename.
Properly set a error message when a client seeker callback is not
defined.
Provide regression test case for bsdcat on empty compressed files
Allow empty files (after filters) in bsdcat command.

This changeset fixes an issue with empty compressed files, i.e.
files that after inflating are of size 0:  bsdcat would report
unrecognized archive format for those because the raw reader is
unable to handle files of zero length.
Add support for lz4 write filter.
Fix build failure with lz4 r120 and later.
Fix build failure on FreeBSD 8.x.
Display filename encoding test names respectively to know what encoding test
was successful, failed or skipped.
Eliminate dead assignment.
Avoid an analyzer error "Dereference of null pointer",
which will not happen but analyzer claims.
Add lz4 filter entry to archive_read_append_filter function.
Update xxhash.c to lz4 r120 version;
o remove xxhash.h, which is unneeded in libarchive and causes
  build failure for function definitions.
o convert single comment statements to block comment statements
  because some C compiler cannot handle it.
Improve lha decompression performance.
Document lz4 compression, lzop compression and other filters
which were not documented in archive_read_filter.3 or
archive_write_filter.3.
Merge pull request #87 from hroptatyr/fix/cat-empty-file

Allow empty files (after filters) in bsdcat command.