existing component tests working again.

MemoryStorage repositioned to be always present,
will work as a write-through cache.
discarded cruft
adding components to entities
creating entities from templates.

retrieval of components by entity.

retrieval of entities with components.
default data test.
passing create options when 'use'ing storage
schema function for returning default values
property orders moved to their own part of the
schema
readjusted property priorities since previous effort
was not taking into account merging of multiple schemas
minor adjustments
added EntitySet, which contains entities matching
some criteria (usually components)
Retrieving entity component from entity set.

the registry itself keeps track of component defs
rather than memory storage.

shifting from using memory storage to using an
EntitySet.
memory storage is no longer keeping track of
componentDefs - this is done by the registry.
removal of components from entities
entity.hasComponent and registry.doesEntityHaveComponent
entity.getComponent and fixes to entity tests
moved test components and entity templates out into 
fixtures.

registration of entity templates now takes an array
as well as a single.
made EntitySet more reliant on Storage - no longer
uses a Backbone collection for entity storage
corrected EntitySet tests
replaced getEntity with hasEntity in storage and
entity_set