Add korean Heaven-Earth-Human IME

I added Korean HEH IME which has different look and input method engine from https://bugzilla.mozilla.org/show_bug.cgi?id=835261. 

Heaven-Earth-Human IME is a default korean IME of Samsung Smart phone. Especially it is good choice for the smart phone that has narrow screen like ZTE Open of mine.

In addition, if it is possible, please add ko-heh at the variable of GAIA_KEYBOARD_LAYOUTS like below:
      GAIA_KEYBOARD_LAYOUTS?=en,pt-BR,es,de,fr,pl,zh-Hans-Pinyin,ko-heh

Thank you.

![jshangul_heh](https://f.cloud.github.com/assets/3491803/2493187/615dc502-b282-11e3-9bbb-121b10390349.png)