Clear the repository for nan porting.
Port greenworks core methods to node v0.11.

Below are porting methods:
  * initAPI
  * saveTextToFile
  * readTextToFile
  * isCloudEnabled
  * enableCloud
  * getCloudQuota
  * activateAchievement
Add LICENSE.
Add missing steamworks header file.
Copy libsteam_api to build directory.

Also fixing some nits.
docs: add readme.
Add test.
docs: add test section.
docs: add building steps for node-webkit.
Add a node-webkit sample application.
Disable deprecated declaration warning in building.

While compiling in nw 0.8.6, there are couples of v8 API deprecated declaration
warning due to v8 API changing. Disable these warnings.
Add atom-shell's sample.
docs: update readme.
docs: update API Reference link.
Port greenwors.isCloudEnabledForUser API.
Port game language related APIs.

* greenworks.getCurrentGameLanguage
* greenworks.getCurrentUILanguage
* greenworks.getCurrentGameInstallDir
Rename steam to greenworks.
Port greenworks.getSteamId API.
Port greenworks.getNumberOfPlayers API.
updated instructions and descriptions