Pgtree

* -C option accepts y/yes/always/n/no/never
* -w n option to disable text wrapping on tty output

* color -C parameter accept always/never/auto (default to auto)

* uses built-in `pgrep` when `pgrep` command not available (AIX)
* built-in supported options: `-f -x -I -u <user>`

* displays custom ps field using `-O <psfield>` (example: `-O %cpu`)
* replace `stime` with `start` ps field on macOS

* define ps headers to fix column widths, more reliable column parsing (macOS compatible)
* use ucomm instead of comm for short exec name
* _AIX still needs a pgrep command to work_

can write :
` pgtree -c bash`
or
` pgtree bash -c`