Add method createNextFolderBatch to create tree structure recursively
Add method createNextFolderBatch to create tree structure recursively

We need to split putnodes commands into small pieces to avoid API
overload, so we are going to iterate through tree structure contained
in mUploadTree recursively, and we will generate smaller batches that
we will send sequentially.

Once a batch has beed created remotely, we will update temp nodeHandles
with definitive ones, and we will process next batch.

meganz/sdk,meganz/sdk,meganz/sdk,meganz/sdk,meganz/sdk,meganz/sdk,meganz/sdk