* Clap has dependencies even with all features disabled.
* The "nightly" feature does nothing, so don't mention it.
* Explain the difference between "unstable" and "nightly" better.
* Split features into groups (default, opt-in, clap-development).
* For contributors: update what tests should be run, and remove make command.
* Removes a repeated word and splits up some long markdown lines.
Also groups features by category and dependencies by feature in Cargo.toml.
The following completion would happen (using example 17_yaml.rs):
```
$ prog <tab>
help subcmd
```
```
$ prog -<tab><tab>
--help -h (Prints help information)
--max-vals (you can only supply a max of 3 values for me!)
--min-vals (you must supply at least two values to satisfy me)
--mode (shows an option with specific values)
--mult-vals (demos an option which has two named values)
--option -o (example option argument from yaml)
--version -V (Prints version information)
-F (demo flag argument)
```
```
$ prog --<tab><tab>
--help -h (Prints help information)
--max-vals (you can only supply a max of 3 values for me!)
--min-vals (you must supply at least two values to satisfy me)
--mode (shows an option with specific values)
--mult-vals (demos an option which has two named values)
--option -o (example option argument from yaml)
--version -V (Prints version information)
```
```
$ prog --mode <tab>
emacs (shows an option with specific values) vi (shows an option with specific values)
```
```
$ prog subcmd -<tab>
--help -h (Prints help information) -B (example subcommand option)
--version -V (Prints version information)
```
```
$ prog subcmd --<tab>
--help (Prints help information) --version (Prints version information)
```
Close#578
By using a build.rs "build script" one can now generate a bash completions script which allows tab
completions for the entire program, to include, subcommands, options, everything!
See the documentation for full examples and details.
Closes#376
Some types weren't viewable in the docs, such as `Values`, `OsValues`,
and `ArgSettings`. All these types should now be browsable in the
docs page.
Relates to #505
By default `clap` now automatically wraps and aligns help strings to the
term width. i.e.
```
-o, --option <opt> some really long help
text that should be auto aligned but isn't righ
t now
```
Now looks like this:
```
-o, --option <opt> some really long help
text that should be
auto aligned but isn't
right now
```
The wrapping also respects words, and wraps at spaces so as to not cut
words in the middle.
This requires the `libc` dep which is enabled (by default) with the
`wrap_help` cargo feature flag.
Closes#428
