Work to tease ONMjs.Store apart more cleanly...

... This commit continues the effort to replace the old Selector-style addressing with the new ONMjs.Address protocol and comprises changes primary to ONMjs.Store and ONMjs.implementation.StoreBase. The whole business of having a base store class is nice but as Store has evolved I've essentially put everything in base nad written stupid forwarding methods from Store. So that's not really a useful base class. In fact it's a performance hit and a distraction in the debugger because superfluous implementation methods show up on the main application-facing class. So base is no longer base. I've moved the constructor logic into Store.constructor proper, and promoted the former StoreBase method implementations for everything except the store reification into the top-level Store class methods of the same name. StoreBase itself, now left with only the store reification method implementations, has been renamed ONMjs.implementation.StoreReifier. Additionally it has been demoted to a contained instance member of ONMjs.Store (so that these methods don't show up at the top-level of an ONMjs.Store object expansion in the debugger).