Validate data.ab in mtc.model.data
Fix error in pseudo-inverse / trial decomposition
Use dev.hold/dev.flush for faster blobbogram
Refactor required columns for data.re

 - no longer specify per likelihood/link since the code assumes the same
   format for all likelihood/links anyway
Refactor: rename network$data to network$data.ab
Add to NEWS
Add unit tests for model$data

This was broken at some previous stage.