upgrade to grunt 0.4

This updates lineman to the latest grunt, and also updates all of the
grunt tasks we use. Here's a quick summary of what I had to do:

 * grunt.utils has become grunt.util -- it's a little sad that this had
 to change in so many places :(

 * The grunt-contrib meta-package doesn't exist (apparently?) for grunt
 0.4, so now we explicitly depend on each grunt plugin that we use.

* The <config:propname> syntax has been replaced with <%= propname %>

* Banner configuration has moved.
Merge remote-tracking branch 'testdouble/master'

made one last update from grunt.utils -> grunt.util here

Conflicts:
	config/application.js
	tasks/configure.js
	tasks/images.js
	tasks/webfonts.js
Merge pull request #34 from kbaribeau/master

Upgrade to latest Grunt