[Owncloud] Pull Request to fix Swift external files

[Benjamin Liles]

Various bug fixes for swift external file support.

- Space free reported as 0 so uploads were canceled
- fopen would not create files, uploads failed
- stat assumed path was an object, no way to stat directories for filecache scanner
- unlink, called when deleting from web ui, assumed path was an object, would not remove directories

Benjamin Liles