Two bugs being fixed here:

1. When we remove a document in a non-batch scenario, we close any
   information related to the open document. If we were in a batch
   scenario, the SetCurrentSolution we do to apply the new Solution
   snapshot didn't go through that. Now we do.
2. UpdateSolutionForBatch wasn't calling the delegates given; this would
   have meant that additional files being added in a batch would have
   been added a regular source files.