fix(test): increase timeout

some qa environments are too slow
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
improve(rest): change variable handling to common variable format

- makes variable representation consistent across all methods
- updates test expectations accordingly

contributes to CAM-765
feat(cockpit-incidents): Add support of incidents

- the cockpit plugins uses the incident infrastructe to show
  whether a process instance/definition failed or not
- refactor the process instance query including pagination and incidents
- add testcases for process instance query

related to CAM-706
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
chore(tasklist): adapt to rest api variable format change

contributes to CAM-765
refactor(RestIT): use installed invoice demo for asserts

reduces external dependencies of the test
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
fix(rest): allow multiple variable filtering expressions in GET queries

- adds tests for this case

contributes to CAM-772
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
Merge branch 'origin/master'