3x-rescan for extracting output from runs again

* Factored extract-output out of run.store.
* _3X_RESCAN_ONLY, _3X_EXTRACT_ONLY for selectively/incrementally
  extracting output.
* Fixed GUI to show only the effective (last) line of output.
* Refactored into find-run-archive.sh for $_3X_ARCHIVE and $_3X_ASSEMBLE
3x-rescan -f for forcing output re-extraction

* Letting extract-regexp scan rusage first because of stdout/err's
  variable size.
Added 3x-rescan in 3x usage
Using GNU Parallel to rescan in parallel
Made 3x-rescan more efficient

by first collecting which output variables to actually extract before
assembling new extractors.
GNU parallel --plain to isolate from user configs
Made number DataRenderer in GUI more robust to

undefined values, which can now be easily observable while a 3x-rescan
or a 3x-define is in progress.
Hard coding GNU time format string for rusage

* Mainly due to the difficulty parsing wall clock time:
  `Elapsed (wall clock) time (h:mm:ss or m:ss): %E`
* Added a line with %e (in seconds) instead.
* Removed Vim formatting of assemble.sh script, since it was interfering
  with the format string for GNU time.
Fixed typo in 3x-plan's generated usage examples
Fixed 3x-reset to leave no bogus RUNNING runs behind