This makes clap wrap the help text according to the terminal width,
which improves readability for terminal widths < 120 chars,
because clap defaults to a width of 120 chars without this feature.
Use clap for argument parsing instead of getopts
Also, make the following changes
* Use `executable!()` macro to output the name of utility
* Add another usage to help message
- refactor internal version specifications to be ">=M.m.p" (where M.m.p is *already published*)
## [why]
Loosening internal version dependencies decreases the coupling between packages such
that packages can be published in a looser order. It allows the packages to be version
updated and published in tandem (ie, by using `cargo workspace ...`). Once published,
the internal versions can then be updated (again, to an *already published* package
version), as needed.
