Tunneling support

[casidiablo]

I'd be cool if sugar could save me from doing things like:

ssh -i ~/.ssh/dev-titan.pem ubuntu@54.226.131.144 -L \
  8888:redis-10144.us-east-mz.3.ec2.garantiadata.com:10144 -N

Something like sugar InstanceName -L redis-10144.us-east-mz.3.ec2.garantiadata.com:10144

[avram]

This is designed to be done with the --ssh-args option: 9621e2e