Unify some constants
Adjust the number of particles in a mole
Simplify ResultWriter a bit
Drop unimplemented ResultWriter.BINARY stuff
textual: s/cant/cannot/
Drop unused scary routine
Extract result writing code into separate class
Rename GridCalc to IGridCalc

Preparation for adding GridCalc class.
Refactor common part of init() into new class
Coalesce two methods into one in parent