Merge code from upstream libtar + bug fixes

All updates and fixes applied from upstream libtar as of
March 1, 2016.

Debug flag is disabled, however non-debug output now
provides 1 line of useful output per object extracted.

I've also merged some fixes from CyanogenMod's
fork of libtar:

From: Tom Marshall <tdm@cyngn.com>
Date: Thu, 11 Feb 2016 16:24:40 -0800
Subject: libtar: Cleanup, secure, and extend numeric fields
Commit: e18b457ea1cbf6be1adc3b75450ed1c737cd82ea

From: Tom Marshall <tdm@cyngn.com>
Date: Thu, 11 Feb 2016 12:49:30 -0800
Subject: libtar: Make file sizes 64-bit clean
Commit: e628c2025549a24018bc568351465130a05daafb

From: Tom Marshall <tdm@cyngn.com>
Date: Thu, 17 Apr 2014 09:39:25 -0700
Subject: libtar: Add methods for in-memory files
Commit: 8ec5627a8ff0a91724c6d5b344f0e887da922527

From: Tom Marshall <tdm@cyngn.com>
Date: Wed, 2 Jul 2014 09:34:40 -0700
Subject: libtar: Fix hardlink extract
Commit: 166d83a51e0c51abcea37694dbd7df92d03c1f56

From: philz-cwm6 <phytowardt@gmail.com>
Date: Sat, 26 Apr 2014 01:11:35 +0200
Subject: libtar: Various bug fixes and enhancements
Commit: a271d763e94235ccee9ecaabdb52bf4b9b2f8c06
(Some of this was not merged in, as better solutions were
available from upstream libtar)

From: Tom Marshall <tdm@cyngn.com>
Date: Wed, 9 Apr 2014 09:35:54 -0700
Subject: libtar: Add const qualifiers to reduce compile warnings
Commit: 0600afa19fe827d06d3fcf24a7aabd52dbf487b4

Change-Id: I6d008cb6fdf950f835bbed63aeb8727cc5c86083
15 files changed