This adds support for Windows VMware Workstation

Conflicts:
	builder/amazon/common/run_config.go

This adds "no-launch" EBS-backed AMI creation, which allows the creation
of these AMIs without launching a new EC2 instance. Instead this builder
is meant to be run on an existing EC2 instance and uses that instance as
a host to attach root EBS volumes, provision in a chroot, etc.

Was getting weird behavior... see
https://groups.google.com/d/msg/golang-nuts/a1kymwSVt2M/FwcCuBl1_48