Remove `context` argument from `Ember.Enumerable#nextObject`
Remove unused property

`Ember.CoreObject#isInstance` is referenced from only test code.
Remove `previousObject` argument from `Ember.Enumerable#nextObject`
Merge pull request #3096 from tricknotes/remove-is-instance

Remove unused property
Update CONTRIBUTING.md

Rephrase "building ember" to only suggest the Vagrant route if the user is having issues installing some of the build tool dependencies.
Add assert that `this` is correct in deferReadiness and advanceReadiness. @stefanpenner / @lukemelia
Merge pull request #3103 from lukemelia/readiness-assert

Add assert that `this` is correct in deferReadiness and advanceReadiness
Handlebars template properties should not be methods
Merge pull request #3105 from sebastianseilund/handlebars-template-is-method

Handlebars template as properties should not be regarded as methods
fix #3093
View event handlers inside eventManager should be wrapped in run loop
quick fix for #3094
Merge pull request #3097 from tricknotes/remove-enumerable-context

Remove unused and complex feature for `Ember.Enumerable#nextObject`
Revert "Merge pull request #3097 from tricknotes/remove-enumerable-context"

This reverts commit d63bd44471f8e9a5329f7781d6bf798671249cad, reversing
changes made to 87e1287a54cc132afd77e5b2d1a1770b775141e4.

Custom enumerables require at least one of a context object or a
previousObject reference.
presendece -> precedence
Merge pull request #3117 from tim-evans/misspelling-in-ember-view

presendece -> precedence
Sync with router.js
Em.Components typo fix - fixes #3118
Merge pull request #3121 from Selvaganeshbsg/master

Em.Components typo fix - fixes #3118
Merge pull request #3106 from sebastianseilund/event-dispatcher-run-loop

View event handlers inside eventManager should be wrapped in run loop