Implement komodo as an explicit state machine

[jondequinor]

There's an implicit state machine in komodo. Make it explicit.

(Assuming we are to expand komodo and do a major refactor)

Rationale
It might be hard to reason about some flows through komodo, especially the file operations in the end (rename, rsync, .delete, etc). Also, if one of these steps fail for some trivial reason, the most safe thing is to re-build from scratch.

So, we might have easier-to-understand code, possibility to more precisely know the state of the build, thus maybe retry from some stage.

The state machine code should not be written by us.