Resharper removed redundancies
Updated IEntityManager
Netcraft.EntitySystemTests.UniverseTests.ShouldEnableAndDisableSystemsOnlyOnceWhenAdded pass
ShouldAddComponentToEntity passed (bad implementation though)
Rather big edit, I should have done smaller commits. But basically we now use ComponentMappers<T> for speed of accessing components.
ComponentMappers now only take reference types
ComponentMapperFactory is now non-generic and non-static to ease with testing. It is injected into the ComponentManager.
UUTs have had their interfaces extracted. Rejoice!