Consistent Cell-Cell ordering, and seperate Cell-scalar semantics.
Tweak docstring and comments
Merge pull request #311 from rhattersley/cell-comparison

Consistent Cell-Cell ordering, and seperate Cell-scalar semantics.
Merge remote branch 'upstream/v1.1.x'

* upstream/v1.1.x:
  Tweak docstring and comments
  Consistent Cell-Cell ordering, and seperate Cell-scalar semantics.
print units on cube

working datetime human read

updated test data to reflect changes