imp(ArgGroup): Add multiple ArgGroups per Arg
Add the function `Arg.groups` that can take a `Vec<&'a str>` to add the `Arg` to multiple `ArgGroup`'s at once.
ex:
```rust
Arg::with_name("arg")
.groups(&["grp1", "grp2"])
```
Closes#426
docs: fix typos
Just caught a couple of small typos while browsing the documentation, I believe the meaning of everything is still conveyed as intended as it's just single words.
Add the function `Arg.groups` that can take a `Vec<&'a str>` to add the `Arg` to multiple `ArgGroup`'s at once.
ex:
```rust
Arg::with_name("arg")
.groups(&["grp1", "grp2"])
```
Closes#426
In usage strings `[FLAGS]` and `[ARGS]` tags are now only added if there are relevant flags and
args to collapse. I.e. those that are
* Not required (`[ARGS]` only)
* Not belonging to some required group
* Excludes --help and --version (`[FLAGS]` only)
Closes#537
Previously, if one ran `<cmd> help help` an additional `help` subcommand was created and a help
message displayed for it. We *could* have just thrown an error `<cmd> help help` but I worry that
the message would be confusing, because something like, "Invalid Subcommand" isn't 100% correct as
the form `<cmd> help <subcmd>` is allowed, and there *is* a `help` subcmd.
This fix correct dispatches `<cmd> help help` to the `<cmd>` help message.
Closes#538
Prior to this fix, runnning `prog help subcmd` would produce:
```
subcmd
USGAE:
[...]
```
Notice lack of `prog-subcmd`. Whereas running `prog subcmd --help` produced:
```
prog-subcmd
USGAE:
[...]
```
These two forms now match the correct one (latter).
Closes#539
Unlike the previous ArgGroups, which made all args in the group mutually exclusive, one can now use
`ArgGroup::multiple(true)` which allows using more than one arg in the group (i.e. they're not all
mutually exclusive). When combined with `ArgGroup::required(true)` this effectively says, "At least
one of the args must be used, and using morethan one is also OK."
Closes#533
Now using `App::set_term_width` will set a wrapping width regardless of terminal size. This can
also be used when no terminal size can be determined (Such as on Windows). All help is now wrapped
at 120 if no terminal size has been specified, or can be determined.
Closes#451
This commit adds support for visible aliases, which function exactly like aliases except that they
also appear in the help message, using the help string of the aliased subcommand.
i.e.
```rust
App::new("myprog")
.subcommand(SubCommand::with_name("test")
.about("does testy things")
.alias("invisible")
.visible_alias("visible"));
```
When run with `myprog --help`, the output is:
```
myprog
USAGE:
myprog [FLAGS] [SUBCOMMAND]
FLAGS:
-h, --help Prints help information
-V, --version Prints version information
SUBCOMMANDS:
help Prints this message or the help of the given subcommand(s)
test|visible does testy things
```
Closes#522
One can now use `AppSettings::DontDelimitTrailingValues` to stop clap's default behavior of
delimiting values, even when `--` or `TrailingVarArg` is used. This is useful when passing other
flags and commands through to another program.
Closes#511
Instead of blindly printing `[ARGS]` when only a single positional arg is present, it will now
print `[NAME]` (or `[NAME]...` for multiple values allowed)
Closes#518
