Change issuegen to use #!/bin/bash due to bash-style echo usage

The \'s are always interpreted in dash/POSIX shell, issuegen expects
them to be ignored without -e.
Merge pull request #135 from vcaputo/issuegen_usebash

Change issuegen to use #!/bin/bash due to bash-style echo usage
Set ClientAliveInterval to three minutes
Merge pull request #136 from crawford/sshd

Set ClientAliveInterval to three minutes
Merge pull request #137 from c4milo/master

Adds systemd network unit for virtual machines running on VMware