Update core grunt NPM package

[netweb]

Update grunt in package.json to v0.4.5

[netweb]

In 5640.diff​:
Update grunt to 0.4.5

• Upstream changelog ​https://github.com/gruntjs/grunt/blob/v0.4.5/CHANGELOG
• Requires npm install to update packages and dependencies

[netweb]

In r8464 Author: johnjamesjacoby
Message: 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.