`serve` command default release mode isn't clear from the help text about webdev

[alorenzen]

This seems to be an issue with the args package, not webdev. The (defaults to on) is added automatically, not by us.
For boolean flags, it seems to only print the default value for on, but not off.

[kwalrath]

Do we need a bug on args?

Also... re-builds should be rebuilds.

[natebosch]

Filed dart-lang/args#114

I'll fix the re-builds to rebuilds thing here.

[grouma]

I believe this is fixed. Our current help message:

Run builders to build a package.

Usage: webdev build [arguments]
-h, --help                        Print this usage information.
-o, --output                      A directory to write the result of a build to.
                                  Or a mapping from a top-level directory in the
                                  package to the directory to write a filtered
                                  build output to. For example "web:deploy".
                                  A value of "NONE" indicates that no "--output"
                                  value should be passed to `build_runner`.
                                  (defaults to "web:build")

-r, --[no-]release                Build with release mode defaults for builders.
                                  (defaults to on)

    --[no-]build-web-compilers    If a dependency on `build_web_compilers` is
                                  required to run.
                                  (defaults to on)

-v, --verbose                     Enables verbose logging.

Run "webdev help" to see global options.

Note that serve does not default to release mode, just the build command.

[grouma]

Oops. Apparently I can't read. This issue was explicitly for the serve command not the build command. Since there isn't work to be done on webdev I'm going to leave this as is. We have the tracking issue in package:args linked above.