Allow native modules to get YAML task vars
Add creates and ignore_failure to shell runners
Fix copy to refer to files/
Exit a failed task properly
Gracefully handle refering to an invalid playbook
Fix error formatting
Refactor FailureResult
Change JSON for a result to be clearer
Add ability to only download a file if missing
Report error on stderr to not blow up remote invocation
Add ability to tag a build as nightly easier