Due to some very old mistakes too many of Delve's flags are declared as
persistent on cobra's root command. For example the headless flag is a
global flag but does not apply to connect, dap or trace; the backend
flag does not apply to replay, core and dap; etc.
Almost all global flags should have been declared as local flags on
individual subcommands. Unfortunately we can not change this without
breaking backwards compatibility, for example:
dlv --headless debug
would not parse if headless was a flag of debug instead of a global
flag.
Instead we alter usage function and the markdown generation script to
strategically hide the flags that don't apply.
Fixes#2361
Go 1.19 also formats doc comments according to the new godoc syntax.
Some of our comments, especially unexported symbols did not conform to
the godoc syntax and therefore are mangled by 'go fmt'.
This PR runs 'go fmt' from go1.19 on everything and manually fixes the
problems.
See also:
https://github.com/golang/proposal/blob/master/design/51082-godocfmt.md
