[Tracker] GetAll method in the API

[Ivan Frade <ivan frade nokia com>]

Hi all,

 We have found that the query "Give me all metadata you know about a
file" is pretty useful, and there were no direct method to do it in the
current tracker API.

 I attach a patch that implements this feature in a new "GetAll" method
in the "Metadata" interface. Everything ok to commit it? Reviews and
comments are welcome.

 Thanks,

Ivan

Attachment: get-all-trunk.patch
Description: Text Data