Current tests pass.
Composition backwards.
Added Dual.
Added identity laws.
Merge branch 'master' of github.com:markandrus/aljebra

Conflicts:
	MonoidTests.js
Back up to speed.
Dual busted, added Endo, Product, and Sum.
Merge branch 'master' of github.com:markandrus/aljebra

Conflicts:
	test/common/test.js
Started on Semigroup.
Added tests for Semigroup.
Better description of the Monoid constructor.
Merge pull request #3 from joneshf/semigroup

Semigroup