* make default timeout 0 to match legacy behavior when new
key is not present in runtime.ini
* Add tests requires
* moving scripts/aws-setup.py into a loadable module
* adding sure to machine-launch-script.sh for nicer assertion style
* Generalize awstools.get_instances_by_tag_type to not assume it is
being called with 'fsimcluster' value, uses tags dict. Created
awstools.get_run_instances_by_tag_type that uses old symantics and calls
the general function similar to launch_run_instances()
* Add `additive` parameter to `awstools.launch_instances()` that controls
whether `count` is the number to be launched in that call or a total number
of instances that should be reached including ones already launched that
match the `type` and `tags`
Abraham Gonzalez