v3.1.16

[3.1.16] - 2022-05-06

Fixes

• (parser) Arg::exclusive overrides Arg::required, like other conflicts
• (error) Don't duplicate arguments in usage
• (error) Don't show hidden arguments in conflict error usage
• (help) New help_template variable {name} to fix problems with {bin}
• (help) Don't wrap URLs

gated behind unstable-v4

• Leading dashes in Arg::long are no longer allowed
• (help) Use Command::display_name in the help title rather than Command::bin_name