- introduce a -o option that displays opaque variables.
- introduce a -x option that displays opaque variables in full.
- deprecate -A in favor of -ao and -X in favor of -ax.
- remove -A and -X from usage() and SYNOPSIS (but not from DESCRIPTION).
- ignore -a if one or more variables were listed on the command line.
- deprecate -w, it is not needed to determine the user's intentions.
- some language and style cleanup in the man page.
This commit should not break any existing scripts.
MFC after: 4 weeks