Hopefully fix a bug in HEAD^^ drunkins_start_job() where $info['process_runner_settings'] was not set.

Half baked support for 'enqueue_by_fetcher' run setting, with lots of @todos. Works on cron (if you hack your fetcher/job to do DrupalQueue::get($this->settings['job_id'])->createItem($item) by itself), not for batch processes.

Rename 'run options' to 'runner settings' and use them a bit more consistently: move 'class' and 'fetcher_class' into them. (Meaning you can theoretically call drunkins_run_start() to run a queue job without defining config in an info hook.) hook_queue_info() definitions now have a 'runner_settings' section but for the rest, code behavior should not have changed.

Use less memory when listing items, by printing out lines of HTML one by one rather than storing them.

Debug/fix issues in HEAD^^; implement run option 'process_items_after_rerun_start' (not tested yet) and make the code consistenly behave like that option is not set by default.

INCOMPATIBLE CHANGE: rename drunkins_continue (internally used context value that can however be set by jobs) to drunkins_process_more.

Implement running start() multiple times, also for queue jobs. ...after reshuffling/redoing code in  _drunkins_start_process() / _drunkins_run_start(), _drunkins_enqueue_items(), _drunkins_finish_process() and (mostly unrelated) renaming _drunkins_calculate_running_info() to _drunkins_calculate_dynamic_info() & symplifying _drunkins_queue_info_alter a bit.

Fix: also properly save context/run options/etc for a queue job with 'drunkins_continue' set. (We logged "There are no items to process" and dropped data.)

Fix PHP5.3? bug related to date_add()ing empty time periods; add ‘run_next’ info key and display it.

Rename ‘cron_min_wait’ queue definition key to ‘cron_schedule’; test period strings and cron schedule strings.

Fix bug in _drunkins_batch_enqueue_items that would cause (batch) jobs that set ‘drunkins_continue’ on start, to only run start() 2 times maximum — because run_info column in the database was wrongly updated.

Fix bug introduced in #39848aa0 -SQLTableImportJob has not worked since 06-11 / the resolveEntityIds() rewrite.

Move (and rename) several settings to the ‘run options’ which used to be in ‘settings’ argument of drunkins_start_job. Specifically:
* logging is now officially a ‘run option’, even though the job itself (+ batch related functions) still has it in settings - this might change.
* override_fetch (items) are now passed in the run option, even though the job’s start() still passes it in context - this might change.
* new fail_silently_if_running
* renamed force_cron

merge drunkins_start_queue_job() / drunkins_batch_start() / drunkins_run_non_progressive() into one drunkins_start_job(). Add ‘run option’ to run a whole progressive batch (i.e. immediately redirect to the progress screen). Return value is now a boolean and the strange two-element array return value is now tucked away into drunkins_last_log().

Move the items passed to a job in ‘drunkins_override_fetch’, from settings to context. The standard job class removes them from context on start() so they are not stored -taking up useless space- for the lifetime of the job.

Rework LinkedCustomerImportJob to also handle non-linked customer entities. This prevents strange caching inconsistencies too.

Change check in EntityImportJob::saveEntity() to account for the fact that we do actually have ‘negative caching’ now (in LinkedEntityImportjob, anyway).

Fix nasty bug introduced in #616d9bfe (3 months ago!) which prevented context from being saved for a cron job - and therefore flushed all items which could not be processed on cron within the same HTTP request. Plus some renaming of variables.