Add missing comparison operators for backend.
Add missing comparison operators for backend.

Also reorder existing ones to have a sensible order.

sintefmath/equelle,atgeirr/equelle,atgeirr/equelle,sintefmath/equelle,babrodtk/equelle,atgeirr/equelle,atgeirr/equelle,sintefmath/equelle,atgeirr/equelle,babrodtk/equelle,sintefmath/equelle,atgeirr/equelle,atgeirr/equelle,sintefmath/equelle,sintefmath/equelle,babrodtk/equelle,babrodtk/equelle,atgeirr/equelle,sintefmath/equelle,babrodtk/equelle,sintefmath/equelle,babrodtk/equelle,babrodtk/equelle