A lot of users expected `color` feature flag and `ColorAuto` etc to
control all colors. Having this extra flag around is easy to miss and
adds to our overall settings bloat, making it harder to find settings
people want.
This completely removes it, rather than make it deprecated like
functions in #2617, because there is extra work to mark things
deprecated as Settings and we should decide on our strategy first before
investing time in addressing that issue.
Fixes#2806
Before #2005, `Clap` was a special trait that derived all clap traits it
detected were relevant (including an enum getting both `ArgEnum`,
`Clap`, and `Subcommand`). Now, we have elevated `Clap`, `Args`,
`Subcommand`, and `ArgEnum` to be user facing but the name `Clap` isn't
very descriptive.
This also helps further clarify the relationships so a crate providing
an item to be `#[clap(flatten)]` or `#[clap(subcommand)]` is more likely
to choose the needed trait to derive.
Also, my proposed fix fo #2785 includes making `App` attributes almost
exclusively for `Clap`. Clarifying the names/roles will help
communicate this.
For prior discussion, see #2583
This PR switches the Arg::Short macro to take a character instead of a string. It removes the hacky code in the Method to_token method and implements the logic for Short when parsing the clap derive arguments.
Fixes#1815.
