[Tizen] Native File System API

Completed features list:

Create file
Read file
Write file
Remove file
Create Directory
List Directory Entries
Remove Directory

BUG=https://crosswalk-project.org/jira/browse/XWALK-1875
> Add you can refer to media.gyp or system.gyp. These gyp files also define "pkg-config" variable.

... In a completely different way than what you did here.