Suppressed noise from 3x-rescan with no runs
Fixed 3x-gui to test X display with xwininfo

instead of naively checking non-empty $DISPLAY.
Made base runner's dequeue more robust.

- Handled cases when runs themselves are removed from queue, but run
  dirs remain.
- Handled cases when run dirs remain but runId was empty.
README proofread by Wonchan (@magnatelee)
Tutorial: explicit program/ prep after quick setup
Tutorial changed URLs to point to gh-pages
3x-init makes sure hardlinks are supported
Tutorial: added missing p values for 2nd example
Releasing v0.9