Basic features for 1.0 beta1

Off the top of my head:

[x] workflow defs loader and parsers
[x] a cli command to list workflow definitions
[x] slot event listener which creates and runs a migration if a corresponding definition is found, setting the slot parameters as references
[x] a workflow step 'filter' which cancels execution if a set of conditions is not matched
[x] a different set of events for workflows than the ones used by std migrations (or just no events at all ?)
[x] injecting the sf logger into the workflow service to allow troubleshooting workflows (instead of a logging-listener as is done for migrations)
[x] a cli command to list executing/failed/cancelled workflows
[x] a cli command to clean up the workflow tables from executed and cancelled workflows
[x] a way to prevent ez slots to be triggered recursively from within workflows if required

kaliop-uk / ezworkflowenginebundle