Driver fails to delete the last subdocument in a collection of subdocuments on a parent document.

[vogelrh]

When subdocuments are added to a property (on the parent) containing a collection of these subdocuments, and then these subdocuments are removed from the parent,the tungus driver fails to remove the last document in the collection. I tracked the bug down to line 101 in the updater.js module in the applyPull method. It appears that the obj parameter needs to be passed into the "matcher" function "as-is", not wrapped in another object.

The applyPull method only appears to be called when the last subdocument is deleted. All other subdocument deletions are handled by the applySet method.