joining multiple matrices -> NewEMSet

[slukowski]

I have attempted to load 3 unaggregated cellranger data sets using LoadCellranger(), extract the 3 matrices, join them and then make a new EMSet. I can create the new EMSet, but he issue I have noticed is that the CellInfo$batch slot does not recognise multiple batches are in there, even though the cell barcodes contain the correct suffix ('-1', '-2', '-3').

An example of the output is here:

> tail(ci)
           cell_barcode batch
2236 TTTGCGCCATTTCACT-3     1
2237 TTTGCGCGTTGTCGCG-3     1

I can probably just correct the data in 'batch', but is probably better to get it automatically

[asenabouth]

Automatic batch recognition is no longer done by ascend, but I could return that functionality or build a JoinEMSet function. I'll flag this as a feature to add.

[asenabouth]

To clarify, automatic batch recognition is only done by the LoadCellRanger function. It is not done by the NewEMSet function.

[asenabouth]

On further thought, it would interfere with later subsetting or if the user decides to define batches differently.