Install proper startup config files for different distributions

As I googled,
Ubuntu will likely switch to systemd after version 15;
Debian will likely switch to systemd after version 8;
Fedora switched to systemd after version 15;
RHEL/CentOS switched to systemd after version 7. So we will
install proper files for different distributions.

Meanwhile, put all init scripts in /usr/share/diamond, users cloud
pick one to meet their environments if they need.

This patch is also related to issue#412