Updates to `package.json`:

* Indent with spaces VS tabs. See: http://yaml.org/spec/1.2/spec.html#id2777534
* Update grunt to 0.4.5.
* Update grunt-wp-i18n to 0.4.4.
* Alphabetize dependencies.

Props netweb.

git-svn-id: https://buddypress.svn.wordpress.org/trunk@8464 cdf35c40-ae34-48e0-9cc9-0c9da1808c22