muntar skips empty files and directories, and is loose with tar entry "type"

[papertigers]

It seems muntar currently doesn't create empty directories on the manta side even though tar(1) itself supports it.

example $ ls
tar1.tar

example $ tar tf tar1.tar
emptydir/
subdir1/
subdir1/test.txt
test.txt

example $ muntar -f tar1.tar ~~/public
/mikezeller/public/subdir1/test.txt
/mikezeller/public/test.txt

example $ minfo /mikezeller/public/emptydir
HTTP/1.1 404 Not Found
content-type: application/json
content-length: 81
content-md5: CbfsD8KXyQ9jOJC6lXjMLA==
date: Thu, 23 Jun 2016 21:30:12 GMT
server: Manta
x-request-id: d9b59f7f-2dfa-4ea2-9c10-802f087a6aff
x-response-time: 16
x-server-name: a28d054b-d8e0-40ab-befc-e5728ef85650
connection: keep-alive

example $ tar xf tar1.tar
example $ ls
emptydir    subdir1     tar1.tar    test.txt

[trentm]

An example tar entry.props from node-tar:

entry.props: { path: 'tmp/c/',
  mode: 493,
  uid: 501,
  gid: 20,
  size: 0,
  mtime: Thu Jun 23 2016 14:27:15 GMT-0700 (PDT),
  cksum: 5485,
  type: '5',
  linkpath: '',
  ustar: 'ustar\u0000',
  ustarver: '00',
  uname: 'trentm',
  gname: 'staff',
  devmaj: 0,
  devmin: 0,
  fill: '' }

The type indicates this is a dir. There are other types that should likely be considered here. See: https://en.wikipedia.org/wiki/Tar_(computing)

E.g. do what on "vendor extensions" values for "type"? Either error (likely the preferred default) or possibly offer an option to ignore entries of unknown type.

[bahamat]

As of #396, muntar is deprecated and will be removed in a future release.