ACT-2037: Performance - Bulk deletion of variables at process end
Merge branch 'master' of https://github.com/Activiti/Activiti

# By fheremans (2) and others
# Via Tijs Rademakers (2) and others
* 'master' of https://github.com/Activiti/Activiti:
  Added source and target container validation + fix osgi test
  Added ENTITY_INITIALIZED for process instances and executions
  Removed warning in test
  Fixed a minor bug in BaseStepDefinitionConverter in which the FormValues were being populated to a list, but never set back on the Property. Therefore Form Properties, like lists/enums were not well formed, with their corresponding values, in the resulting BPMN model.
  doc-fix (ENTITY_INITIALIZED)