master branch of mongo-c-driver required to work with recent MongoDB

[assen-totin]

Currently, the mongo-c-driver submodule liks to branch gridfs_id of that project. However, this branch does not work, at least with recent MongoDB. On Mongo 2.4.6 I get the file name and length, but file retrieval fails, because mongo_cursor_next() function of the driver wrongly reports there is no data to read (cursor->reply->fields.num is always 0).

This issue seems to be fixed in the master branch of the mongo-c-driver; at least, file retrieval works properly. To get it working, do not do 'git submodule init...' but simply do a 'git clone' of the submodule repo (which will give you the master branch).

Please, update the .gitmodules path.