Consider removing the orchestrator for provisioning Apps

[mebster]

Related to the reduction of supported connectors (#253)

What about build image?

[konstan]

• SS starts VM with node executor (NE)
• NE does the needful to produce the increment
• NE does a minimal local cleanup
• NE declares done to SS and asks to persist the increment
• SS calls IaaS to produce new image
• SS recovers the new image ID and sets it on the module for the cloud

SS "takes" the role of the orchestrator: provision VM, create image on IaaS, recover image ID and set on the module.
NE runs 1.-3. App Workflow steps.