With CentOS 7 and Ubuntu 16.04 (to be released) using systemd
it is preferred that CloudStack's Agent is also being started using
systemd.
This commit includes a service file for the CloudStack Agent with
a wrapper script which actually executes Java
It no longer uses jsvc for daemonizing and thus this requirement
has also been dropped for CentOS 7 packaging.
The Agent log output to stdout has also been modified to no longer
include the timestamp as this is done by journalctl.
This has been tested on a CentOS 7.1 machine and the Agent starts,
stops and restarts properly.
