Add ‘tools-aws’ VM for AWS deploy. Add placeholder ‘omni’ VM.

AWS:
* Add ‘tools-aws’ VM with AWS provider to Vagrantfile
* Add instructions in README-Vagrant.md
* install-mastercoin-rools-root.sh now takes user & group as arguments
* setup-aws-template.sh to set AWS private shell variables
* unset-aws-private.sh to clear AWS private shell variables

Omniwallet VM placeholder (for Faiz)
* Add ‘omni’ VM to Vagrantfile
* Placeholder shell scripts (copies of mastercoin-tools scripts)