[Add] GDFileManagerKit (0.0.1)

GDFileManagerKit lets you access Dropbox, Google Drive, SugarSync and WebDAV with a consistent,
NSFileManager-like API.

Features of GDFileManagerKit include:

* Cached file metadata.  Old metadata is re-validated where possible making API calls more efficient.
* Cached file downloads.
* Chunked upload / downloads where available for reliability in intermittently connected environments.
* Copy/Delete/Move file operations.