Fix ABI on dragonfly

Define dragonfly as legitimate value for elf notes and also updates the ABI
version which is different than FreeBSD. FreeBSD only needs whole numbers for
the version (e.g. 8,9,10) while DragonFly needs evenly numbered point versions
(e.g. 3.4, 3.6, 3.8).

The development branches are oddly numbered (e.g. 3.3, 3.5) but packages created
by these branches should be valid for the upcoming release, so 3.3 will round to
3.4 for the ABI version.
Remove usage of deprecated libarchive function

Add macro for older libarchive support like in FreeBSD 9 and FreeBSD 8
archive_read_finish is deprecated

Reported by:	John Marino
Fix multirepo

Reported by:	kwm
Fixes:		442
file_exists needs 2 arguments not just one

Conflicts:
	libpkg/pkg_repo.c
Return an error in case a update did faile in multi repository mode
Merge remote-tracking branch 'upstream/master'