Add cross-platform service start/stop support

Change-Id: I421884d6326bed3bc81deaa6389e06647c1b9296
Remove debug puts

Change-Id: I40c4497b52ccc950fd70c3ceb7a6654a98a173da
Use system file.truncate

Change-Id: Ic95dc266b77411357f211509be195e8686042fea
Move update_hostname to template

Change-Id: I4f773e030e923bbc105603c6031a89df532fa51f
Use Bosh::Exec.sh for iptables commands

Change-Id: Id146563bca2ad6cd09cb208d89ff12bae7b8cc59