In console (dev mode) type getModel() to get model

This will now return the updated model after a reload, and will prevent false negatives where bugs related to a variable named 'model' are masked by having a global named 'model'.
Rm unnecessary evil: true jshint option
Reset/reload buttons for callAt/callEvery demo

[#57569858]
simplify callAt/callEvery; reset them on model reset

[#57569858]
propertySupport bug: can't remove first observer

[#57569858]

Needs tests!