Promote debhelper compatibility level to 9.

The compat=9 overlay level is supported by Debian Wheezy, Ubuntu Lucid,
and all other current DEB platforms.
Create a ufw firewall template for SoftEther.

Install a `/etc/ufw/applications.d/softether` file that describes
network ports to keep open for the default SoftEther configuration.
Update changelog for 4.06.9437-3~trusty release