Add simple core.async component.

Remove println from scheduler and pipeline.
Messages from queue are, for testing purposes, just printed.
WIP: Add queue worker to trigger data operations.

- For now there is only one channel: measurements
- Not all measurements are put on queue - need to investigate why.
Fix missing where clause from sensor metadata.
Add repl ns to execute pipeline functions in repl.

Rollups can be triggered through sending job down the pipeline
using repl or scheduler.
Dirty start/end dates are reset after re-cacalculation (to nil
if the new dates are within old recalculation's range, or to new dates).