Removed scalar from GroupAction.
Semigroup scalar is not available anymore in the GroupAction instance.
Removed scalar from SignAction and Torsor.
Merge pull request #299 from denisrosset/topic/remove-action-scalar

Topic/remove action scalar
Pedantically correct spelling in User's Guide

…though it warms my heart that the letter order was reversed in a sentence explaining the reversed order of *Order explanations.
Merge pull request #302 from barnardb/patch-1

Pedantically correct spelling in User's Guide