Squashed new proc pool changes.
Record pool size to avoid using multiprocessing.Pool internals.
Restored missing "if" statement.
Retrieve final proc pool results

Also removes extra blank lines before scheduler methods.
Merge branch '119.iso8601-cycling' into procpool
Turn off thread ID print.
Restored shutdown logging (accidentally deleted).
Comments updated.
Process pool only - removed threads.
Removed lsof logic (not required for proc pool).
Changed misleading "submitting now" message.
tests - bash 4.2.0 compat
Fix UTC mode clock-trigger test.
Merge pull request #1012 from hjoliver/procpool

Process pool to replace command execution threads.