* Add app package and move logic over from api package
* Change app package functions to return errors
* Move non-api tests into app package
* Fix merge
* Implemented initial changes for files table
* Removed *_benchmark_test.go files
* Re-implemented GetPublicFile and added support for old path
* Localization for files table
* Moved file system code into utils package
* Finished server-side changes and added initial upgrade script
* Added getPostFiles api
* Re-add Extension and HasPreviewImage fields to FileInfo
* Removed unused translation
* Fixed merge conflicts left over after permissions changes
* Forced FileInfo.extension to be lower case
* Changed FileUploadResponse to contain the FileInfos instead of FileIds
* Fixed permissions on getFile* calls
* Fixed notifications for file uploads
* Added initial version of client code for files changes
* Permanently added FileIds field to Post object and removed Post.HasFiles
* Updated PostStore.Update to be usable in more circumstances
* Re-added Filenames field and switched file migration to be entirely lazy-loaded
* Increased max listener count for FileStore
* Removed unused fileInfoCache
* Moved file system code back into api
* Removed duplicate test case
* Fixed unit test running on ports other than 8065
* Renamed HasPermissionToPostContext to HasPermissionToChannelByPostContext
* Refactored handleImages to make it more easily understandable
* Renamed getPostFiles to getFileInfosForPost
* Re-added pre-FileIds posts to analytics
* Changed files to be saved as their ids as opposed to id/filename.ext
* Renamed FileInfo.UserId to FileInfo.CreatorId
* Fixed detection of language in CodePreview
* Fixed switching between threads in the RHS not loading new files
* Add serverside protection against a rare bug where the client sends the same file twice for a single post
* Refactored the important parts of uploadFile api call into a function that can be called without a web context
