Fix most jshint issues

- Take grunt into use, so you can simple `grunt` to run jshint on the source
- Fixed all but `eval` jshint issue
- Refactored `fromCharCode` - IMHO it's now simpler to understand (and the test suite seems to run a little faster)
- Edited `index.html` and `test.html` in `src/` to use actual lib
    - next step would be to port tests to be run by grunt

I use single `Array#reduceRight` in the code.