fix(engine): fix instance suspension with call activities

- a finished called process instance should not be able to resume
a suspended parent

related to CAM-447
feat(engine): add explicit exception type for suspension issues

- thrown if an interaction with an entity (task, execution, definition)
is disallowed, because the entity is suspended

related to CAM-447
chore(engine): make execution suspension feature consistent

- all actions causing token manipulations fail, if an execution is suspended
- everything else (setting variables, etc.) is allowed

related to CAM-447
chore(test): Add test for process instance ctrl

- add testcases to test the selection behavior (from tree to diagram and
  from diagram to tree) in the process instance controller

related to CAM-719
chore(engine): make task suspension feature consistent

- all actions changing task lifecycle state are disallowed (claiming,
delegating, etc.)
- all actions simply changing properties are still allowed (set variables,
add comments, etc.)

related to CAM-447
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
style (engine): fixed wrong name of method parameter
Merge pull request #12 from berndruecker/master

Thanks Bernd!
fix(jboss): fix handling of default process engine

- make sure default process engine must not be named default

related to #CAM-929
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
feat (engine): Added support for link events

closes #CAM-437
chore(engine): fix typo in classname & add license

- fix classname IntermediateCatchLinkEventActivit{i->y}Behaviour
- add license Header

related to #CAM-437
chore(qa): unify polling interval
chore(qa): add baseline for jobexecutor timeouts
docs(migration-scripts): clarify a comment of an upgrade step

related to CAM-897
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
fix(engine): serializable vars in shared engine

- use ReflectUtil for deserializing process variables
- allows to use serializable process variables in combination with shared
  process engine.

related to #CAM-907
Merge branch 'master' of github.com:camunda/camunda-bpm-platform
feat(vars): Add variable instance query

- Add to the runtimeService the method 'createVariableInstanceQuery()' to
  create a variable instance query
- Implement the variable instance query
- Add testcases to test variable instance query

related to CAM-941
feat(rest): expose filtering by suspended tasks and executions

related to CAM-944