Merge pull request #1272 from knockout/855-subscribe-to-deferred-computed

Evaluate deferred computed on subscribe
Update code to set the value to the current UI selection when the value is rejected. Update test to check this.
Reinstate behavior when clearing value for size > 1 select.
In selectExtensions, use === instead of == where possible.
Treat functions and observables differently in ko.bindingContext. If a function is provided, the return value of the function becomes $rawData, and if an observable, will be unwrapped.
Merge pull request #647 from knockout/647-allow-unselected-value

Support select value not in options list, optionally
Merge pull request #1255 from knockout/1255-track-observables-in-getBindingAccessors

Track observables accessed in getBindingAccessors
Don't export computed object in ko.computedContext.
Check that disposeWhenNodeIsRemoved is a node before added dispose callback.
Merge pull request #627 from knockout/627-computed-context

Provide access to dependency count within computed function
New spec showing deferEvaluation computed sometimes take dependencies after disposed
dependentObservable will no longer evaluate if it has been disposed
Prevent a computed from taking dependencies if it's disposed within the evaluator.
Minor style tweaks
Merge pull request #1209 from knockout/1209-prevent-disposed-computed-from-taking-dependencies

evaluating a disposed deferred dependentObservable causes it to take dependencies
Add propertyChangedFired=false to focus handler.

propertyChangedFired is always set to true.  Added code to set it to false when an input gets focus.
Amend spec to demonstrate necessity of change
Merge pull request #1289 from knockout/1289-computed-test-disposalnode

addDisposeCallback to "not nodes"
Add spec about $rawData value in extended context when binding to a function that returns an observable view model.
Merge pull request #1306 from knockout/1247-propertychangefired-bug

1247 propertychangefired bug