modified cli.js so that it can read from piped input by default

[ben-bradley]

I modified cli.js so that it expects stdin by default if no arguments are provided and will detect when no stdin is provided:

• stdin piping before:

$ cat package.json | js-beautify -f -
{{ pretty output }}
$ cat package.json | js-beautify
Must define at least one file.
Run `js-beautify.js -h` for help.

• stdin piping after:

$ cat package.json | js-beautify -f -
{{ pretty output }}
$ cat package.json | js-beautify
{{ pretty output }}

• before with no stdin:

$ js-beautify -f -
{{ hangs until ctrl+c }}
$ js-beautify
Must define at least one file.
Run `js-beautify.js -h` for help.

• after with no stdin:

$ js-beautify -f -
No input detected
Run `js-beautify.js -h` for help.
$ js-beautify
No input detected
Run `js-beautify.js -h` for help.

[bitwiseman]

Interesting. Please update the python and the tests too.

[ben-bradley]

@bitwiseman I'd love to, but I have no experience with the test framework in this project or Python and I'm afraid I'd do more harm modifying that piece of code.

[bitwiseman]

That's unfortunate. This looks like a good change. In any case, it is an api change, so it will have to wait both until the next version and I have time to look at porting it to python and fixing the tests. \

Thanks for starting point!