Created Grunt.js based build
* provided package.json file
* separated qrcode.js into separate files under src/ using common.js format
* provided .jshintrc and .jsbeautifyrc files, made sources adhere to rules
* Gruntfile.js using jshint, jsbeautifier, browserify and uglify to compile into lib/ directory
Merge pull request #2 from dertseha/grunt_build

Created Grunt.js based build