Set default CLOUD to 'auto', which will try autodetect the cloud
provider.
Each cloud can have an autodetect script which should print:
<priority> <cloud>
if cloud was detected.
* switch from phase functions to variables containing list of actions
* init actions prefixed with 'init__'
* refine output during init
* add syslog entries
* add --setup for putting init scripts in the right runlevel
* save `user-data` during main `tiny-cloud` init script instead of `tiny-cloud-final`
* allow manual setting of bootstrap state with...
* `service tiny-cloud complete`
* `service tiny-cloud incomplete`
* use `${VAR:=default}` idiom instead of `VAR=${VAR:-default}`
* fix inconsequential typo in `imds-net-sync`
