Merge pull request #25 from ToonTalk/master

Updating gh-pages to master
Using addEventListener

Instead of setting onchange and onclick. This way can have more than one
handler/listener.
Proper fractions weren't displaying the operator

Except when they were between 0 and 1.
Merge pull request #26 from ToonTalk/gh-pages

Bringing master up-to-date from gh-pages commits