Squashed 'posh/posz/' changes from 7d74d37..83e1464

83e1464 Add `-c` option, and fix tab expansion issue.

git-subtree-dir: posh/posz
git-subtree-split: 83e14647e96adcec4de4f238e78d37eb85279a75
Merge commit 'a32ed8c7f0aff7dc36a44b261a4c3e396232856e'