Revert "fix: `opts.polling` changed to `opts[watch-polling]`"

This reverts commit 52789f5b19177e2d72a743fa33f3a7c9c020a910.
Revert "mov: Change the option name `--polling` to `--watch-polling`, and only leaves the long option name."

This reverts commit 08f6c65c3bcfdc0e7c129e7da1bab3a823f38c38.
Revert "add: Stat polling support while `fs.watch` doesn't work."

This reverts commit 2853e718f289d7f6c699829ade4151a1a30e7e1b.
Remove old Node pre-0.6 warning.