addresses issue #2 and other things

Squashed commits:
[1f00218] many changes
- removed bower_components from version control
- updated & moved ng-prettyjson.html into demo/ directory
- added .bowerrc to specify "lib" as bower directory
- added "lib" to .gitignore
- further split up ng-prettyjson.js for ease of unit testing
- better performance when making entities
- added tests for markup() and makeEntities() functions
- updated travis.yml to use grunt-cli
- updated Gruntfile.js to have "unit" and "continuous" targets for test; "unit" will run and watch for updates while "continuous" is best used by travis
- renamed MIT-LICENSE.txt to standard LICENSE
- updated test script of package.json to use Grunt

note: unless you want to run Karma directly by some other means, with grunt-karma the karma.conf.js file(s) are probably not needed.  I haven't removed them, because other IDEs (like JetBrains products) can run Karma directly if given a configuration file, but cannot do this w/ Grunt.
[7c65f89] performance / test improvements, fixed possible issues with embedded functions, fixed issues with element syntax, no longer requires 'json' key in object, and if in attribute syntax, 'json' attribute no longer necessary.  tried to not break anything.  updated tests & version

Squashed commits:
[4c9c2e8] performance / test improvements, fixed possible issues with embedded functions, fixed issues with element syntax, no longer requires 'json' key in object, and if in attribute syntax, 'json' attribute no longer necessary.  tried to not break anything.  updated tests & version-- need to update docs.