Define print methods for WideSomaLogicData, LongSomaLogicData

[Richard Cotton]

From Martin Morgan:

The following is open for some discussion. For whatever historical reason the format for expression data is (a matrix of) features x samples, i.e., the transpose of the output of readAdat(). I personally think that this how your package should present the data to the user. Data representation inside the package is at your discretion.

I don't quite get the bit about transposes: getIntensities already allows you to choose whether you want samples or features in the rows.