chore(webapp/styles): remove styles folder
feat(cockpit/style): add new styling for activity instances

related to CAM-718, CAM-1848
chore(engine/REST): remove redundant toString in historic process instance test
chore(maven): add BPMN model API to engine and parent pom

related to #CAM-1857
chore(bpmn-api/deploy): add posibility to deploy a BPMN model instance

related to #CAM-1857
feat(bpmn-api): add access to the BPMN model API from java delegate code

Add an interface to access the current model instance and model
element instance. And implement and test it for the following
combinations:

* task listener user task (start, assignment and end event)
* java delegate on service task
* execution listener:
  * process (start and end event)
  * start event (end event)
  * sequence flow (take event)
  * intermediate catch event (start and end event)
  * gateway (start and end event)
  * user task (start and end event)
  * end event (start event)

As a bonus all test processes were created with the BPMN model API.

related to #CAM-1857
feat(bpmn-api): get BPMN model instance using the repository service

related to #CAM-1856
chore(cockpit/dateFilter): adjust style of input field

related to CAM-1613
fix(cockpit/diagram): deselect current selection

Chrome behaves sometimes confusing, the mousemove event triggers even if
no mousemovement happened after a mousedown event. That's why sometimes it
is not possible to deselect your current selection on the diagram.

This commit provide a workaround to handle this strange behavior.
feat(distro): add BPMN model API to all distros

* add BPMN model API to all application server distributions
* add integration tests verifying that BPMN model api can be used inside deployed process applications
* adjust JBoss Subsystem: module dependencies to BPMN model api modules are now added as implicit module dependencies.

related to #CAM-1860
fix(cockpit/diagram): fix compile failure in directive
chore(cockpit/tree): improve activity instance tree

* order children after activity instance id
* open activity instance tree node if a nested activity instance is
  selected on the diagram

related to CAM-1818
chore(cockpit/js): clean up js code
fix(engine/scopeActivity): do not remember current activityInstanceId

This commit extends the hack around the execution tree structure which is not in sync with the activity instance concept:

The current activity instance will be only remembered if:

* the execution is a scope,
* the activity is a scope and
* the behavior of the activity is a CompositeActivityBehavior

related to CAM-1883
chore(parent-pom): add xml-model dependency

related to #CAM-1860
impr(cockpit/tree): adjust style to display activity instance tree

related to CAM-1848, CAM-748
fix(cockpit): refresh view on selection in a proper way in cockpit

related to CAM-1864
feat(engine/history): log user task operations

- Introduce new User Operation Log logging operations
  performed by a user (such as "claim task")

- Populate Operation Log with Task Operations

- Deprecate TaskService.getTaskEvents(): evnets are now retreived
  from Operation Log instead of Comment Table

- Provide Query for operation log.

- Provide Sql migration scripts.

related to #CAM-1756, #CAM-1758, #CAM-1700
fix(engine): string concat on mysql

use mysql "CONCAT(...)" function instead of ANSI "||"

related to #CAM-1758
fix(engine/ci): exclude TaskEventsTest for hist levels