More accurate seeking with libdvdnav
http://trac.xbmc.org/ticket/12212 applied to current codebase
full credit should go to gnosygnu, see
http://forum.videolan.org/viewtopic.php?f=32&t=76308&start=20#p316583
Add diff in lib/libdvd/patches for tracking against upstream
Update to rev. 7 from upstream
http://lists.mplayerhq.hu/pipermail/dvdnav-discuss/2012-December/001837.html
Merge pull request #2957 from jmbreuer/upstream-libdvdnav-seek

More accurate seeking with libdvdnav