craue/CraueFormFlowBundle — pull request #148 by craue (2014-08-21 22:48:12+00:00)
Title: restructure data storage

This changes the structure of saved step data to allow managing it for further features, like #116.
With the old way, it was not easily possible to analyze the stored data from outside a flow. Now, by adding some metadata, it's possible to scan for flows and their instances, or to drop data of all flows.

BC break: The new structure is incompatible to the old one, thus currently running flows will appear being reset. At first I planned to add a migration mechanism, but because a custom `$stepDataKey` could have been set for each flow, I dropped that idea.