[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
Tizen doesn't define TZ_ mapping. Please refer to https://wiki.tizen.org/wiki/Multi-user_Platform_Metadata