Add empty files
Add interfaces.

* FileInterface
* FileRepositoryInterface
* FileStorageInterface
Reduce methods of  FileInterface
Merge pull request #71 from toiee/add-file-interfaces

Add file interfaces
Fix plugin utility parseColumnData method

Resolve parameter "3+1"
Merge pull request #73 from toiee/fix-plugin-utility

Fix plugin utility parseColumnData method
Merge branch 'master' into fix-cols-plugin