Add, hopefully, better support for Redhat/CentOS 7 considering the move to systemd.  Add support for getting a systems ip address without necessarily requiring ifconfig being available on the system.

git-svn-id: https://svn.code.sf.net/p/freeghost/code/trunk@2848 71f96598-fa45-0410-b640-bcd6f8691b32
Merge svn with dev-branch