package.json: Remove "preferGlobal" option

[feross]

We use js-beautify internally, as part of standard. Our users get this warning whenever they npm install standard:

npm WARN prefer global [email protected] should be installed with -g

It's no longer a best-practice to use preferGlobal for npm packages that merely contain a command line program. The command line program should be the only way to use the package.

Thoughts?

[bitwiseman]

Seems reasonable. it is up to the user if they want to install global or not.

[feross]

Cool, thanks!