[BUGFIX beta] Remove false attribute from Ember.View

In IE8 (or older), `jQuery.fn.prop` always update DOM against our
expectation.(This is a jQuery bug but it couldn't fix)
ref: http://bugs.jquery.com/ticket/13558

So the following test is failed due to `view.$().attr('foo')` returns `"false"`.:
* https://github.com/emberjs/ember.js/blob/a449d445/packages/ember-views/tests/views/view/attribute_bindings_test.js#L126

To avoid this issue, `removeAttr` should be called when `null`, `undefined` or `false` is given as value.

But this way contains incompatible changes:

Before:
``` javascript
view.set('checked', false);
view.$().prop('checked'); //=> false
```

After:
``` javascript
view.set('checked', false);
view.$().prop('checked'); //=> undefined
```
[Bugfix beta] improve action without actions hash deprecation warning
[BUGFIX] Create _super when applying mixins. Use __nextSuper in wrappers

This sets _super on the context of all Ember objects, and also sets _super
on mergedProperty contexts if they have a property that is a function.

Fixes #3523, discussed in #3683
[BUGFIX release] Reduce read-only calls to meta
[BUGFIX release] Pass meta into watchKey when possible
[BUGFIX release] Reduce even more meta calls by passing it along in other places
[BUGFIX release] Reduce even more meta calls by passing it along in other places (doh, missed one)
[BUGFIX beta] fixed issue with transition.resolvedModels

Already-resolved parent models weren't showing
up in modelFor hook post-refactor

cc @wagenet
Merge pull request #3683 from mixonic/super

[BUGFIX] Ever-present _super, avoids infinite loop case
[BUGFIX release] finishChains was modifying meta incorrectly
[FEATURE ember-eager-update-url] Eagerly update link-to urls

Previously, the url in the address bar would only update
at the very end up the transition. This change causes the
url update to happen immediately unless the transition
was aborted/redirected within the same run loop, which
provides for a better UX 99% of the time.
Merge pull request #4122 from machty/eager-url-update

[FEATURE ember-eager-update-url] Eagerly update link-to urls
Remove a .swp file
Update ember-dev
Use expectAssertion instead of manual assert stubbing
Introduce expectDeprecation. Remove TESTING_DEPRECATION.
[BUGFIX release] We don't need to call didChange after we've copied
[BUGFIX beta] Silently fail when disconnecting from an inactive view
[FEATURE ember-eager-update-url] tweak for hash location

Need to strip hash before eagerly updating url.
[FEATURE query-params-new] active support for numbers and arrays

This should fix  #4118. QPs always get interpreted fromt the URL as
strings. This commit updates router.js so its supports numeric and
array QP when determining active state.

This commit also depends on https://github.com/tildeio/router.js/pull/75