add es6 support by jsdc

Hi there, I have write a program `jsdc` to compiler es6 to es5, it can works on both node.js and browser.

Features:
* Recognise and ignore es5 syntax
* Keep global variables
* The number of rows of code is consistent
* No preset script
* As simple as possible

Could u put this on your es6-compat-table? Thx!

* github: https://github.com/army8735/jsdc
* demo: http://army8735.me/jsdc/demo/