Added some additional information to execution listener in the documentation (i.e. that the execution listener can capture events of gateways and of intermediate throw events, too) to prevent some confusion.

the spec

Adding documentation on intermediate throwing compensation events - restructured section, adding paragraph about process variable snapshots

Adding documentation on intermediate throwing compensation events - adding additional note illustrated by an example process

ACT-1107: Added docs and execution listeners to intermediate throw none event including parse listener (for KPI support)

User Guide: As I couldn't see any support for Drools rulesets in the current implementation and test case of the Business Rule Task, I removed the according phrase from the documentation

ACT-564: Added activiti extension to specify initial value for due date when task is created + docced and tested