Refresh network interfaces each boot

This is necessary because Mavericks doesn't automatically detect any
changed network interfaces until the Network Preference pane is opened.
By running "sudo networksetup -detectnewhardware" on each boot, the new
network adapters are detected.

This change adds a Launch Daemon, which will run every time the machine
is booted, that will refresh the network adapters configuration. This
ensures that the machine will always have connectivity automatically
immediately after boot.
Merge commit 'dc88b5f2c8666d79d4f3e295d336a87704624df0'
detect new interfaces script: don't use sudo
detect new interfaces script: set perms explicitly