Add Grunt.js for task management

- JSHint to check for standard javascript usage
- concat to concatate source files
- uglify to compress source files

Setting up the default task to run jshint and karma.
Fix jshint warnings about strict mode and expressions

Setting 'use strict' to false, which is the default and removing it from
the individual test files. Also allowing jshint to ignore warnings about
using expressions in the js tests.
Remove tabs in index.html in favor of 2 spaces