SObject.includes() can accept has_many associations
An association shouldn't define its eager load projections
Cache has_many association when no associated records exist
SObject HasManyAssociation should be empty array when no records exist
Merge pull request #78 from DanOlson/includes-has-many

SObject.includes() can accept has_many associations
Don't mutate classes during test runs

Conflicts:
	spec/spec_helper.rb
Remove needless requires; eliminate ivars in specs
Run specs in random order