Remove automatic projection instantiations in Context::_initializeProjections()

[alexlawrence]

Why are projections automatically instantiated once upon initialization of a context? This leads a possible computation overhead, to event handlers which will not be unsubscribed and it could lead to unexpected behavior.

https://github.com/efacilitation/eventric/blob/master/src/context/context.coffee#L615

Actually the intent was to make it easier to use a projection initially. But meanwhile I would say its way to implicit - so from my point of view it would be OK to remove automatic projection initializing.