separated getCSV() from saveCSV()

This way you can modify the csv file before saving.
removed distributed parts form calculate.single()

It had some type checking stuff left over from when calculate was one
function
moved calculateAll() to calculate.all()
spectragen uses settings.lua
improved a comment in calculate.all()
loadData():bincount in returned as spec.getN()

No need to return it separately, also this method wouldn't work anyway.