* Prepare unit tests for running without tx-pool job queue
why:
Most of the job queue logic can be emulated. This adapts to a few
pathological test cases.
* Replace tx-pool job queue logic with in-place actions
why:
This additional execution layer is not needed, anymore which has been
learned from working with the integration/hive tests.
details:
Execution of add or deletion jobs are executed in-place. Some actions
-- as in smartHead() -- have been combined for facilitating the correct
order actions
* Update production functions, remove txpool legacy stuff