Updated makefile to allow for DESTDIR

Allows the makefile to install to a root defined by DESTDIR, if DESTDIR is provided in the command line.  Otherwise, it installs to the default location
Fix Darwin version numbering
code: add support for all syslog facilities, see https://github.com/HardySimpson/zlog/issues/43
Merge pull request #45 from igorefremov/patch-1

Updated makefile to allow for DESTDIR
Merge pull request #46 from basho/bugfix/osx-version-12

Fix Darwin version numbering
Merge remote-tracking branch 'hs/master'