feat(stacktrace): Get job stacktrace

- add a GET to get the stacktrace of a failed job

related to CAM-976
feat(message): Add message column to incident

- an incident now contains a message column
- when recursive incidents will be created, only the root incident
  contains the message
- a root incident has as cause incident id and root cause incident id it
  own id (reflexiv)
- updated upgrade scripts

related to CAM-976
feat(incidents): Show incidents in cockpit

- in the process instance view now the corresponding incidents will be
  shown
- the selections in the process diagram and activity instance tree will
  set as search parameter in the URL -> if you refresh the page, the
  selection will be still selected
- Implementation of a custom incident query

relate to CAM-976
Merge branch 'master' of github.com:camunda/camunda-bpm-platform

Conflicts:
	webapps/camunda/webapp/src/main/webapp/assets/vendor/camunda-common/directives/stateCircle.js
	webapps/camunda/webapp/src/test/java/org/camunda/bpm/cockpit/plugin/base/ProcessInstanceResourceTest.java
	webapps/camunda/webapp/src/test/java/org/camunda/bpm/cockpit/plugin/base/pa/CreateIncidentsDelegate.java
	webapps/cockpit/cockpit-webapp/src/main/webapp/app/cockpit/directives/stateCircle.js
	webapps/cockpit/cockpit-webapp/src/main/webapp/assets/vendor/camunda-common/directives/stateCircle.js