add more explanation of license

[suggested](http://logbot.g0v.tw/channel/g0v.tw/2013-08-16#648) by
pofeng_ in #g0v.tw on freenode.
Add a link to user input page

Add a link in `popup.html` to [user input
page](http://g0v.github.io/laweasyread-front/userInput.html).
Copy `embedded2.js` from `gh-pages` branch

Just a copy to make sure one can find everything in master branch.
Delete unused old files.
Fixing #4, but not done yet

* `eval` is used only for debug and now deleted.
* For `innerHTML`, there's a new function `json2dom` in `LER.js` now.