fix emberjs/website#1027 with unique header title
Merge pull request #3864 from mikepmunroe/master

fix emberjs/website#1027 with unique header title
Update header comment format to keep it on minify

Some minifier keep header comment over its format.

1. YUI Compressor
It keeps the header comments beggining with `/*!`
* http://yui.github.io/yuicompressor/css.html#special-comments

2. Closure compiler
It keeps the header comments containing `@license` or `@preserve`
* https://developers.google.com/closure/compiler/docs/js-for-compiler#tag-license

I think header comment is very important because it includes its own license.
Inspect `content` in assertion message of '#each' helper

I improved assetion message to inspect `content` of `#each` helper.

before:
> You passed [object Object] (wrapped in (generated ontology.index controller))

after:
> You passed '{}' (wrapped in (generated ontology.index controller))

"[object Object]" should be inspected for kindness of debugging.
Merge pull request #3865 from tricknotes/update-header-comment-format

Update header comment format to keep it on minify
Merge pull request #3866 from tricknotes/improve-assertion-message

Inspect `content` in assertion message of '#each' helper
[BUGFIX beta] contextualizeBindingPath should be aware of empty paths
[FEATURE propertyBraceExpansion] Ensure __ember_observes__ is set properly.

The refactor in 5d95885 to allow only the declarative form of expansion
caused the `__ember_observes__` property to be unset when the feature
was enabled.

This was identified while fixing the Travis asset publishing and build
failures in #3863.

@twokul / @rjackson

/cc @hjdivad
Merge pull request #3875 from rjackson/fix_propertyBraceExpansion_prototype_expansion

[FEATURE propertyBraceExpansion] Ensure __ember_observes__ is set properly.
Merge pull request #3870 from marcioj/3860_fix

contextualizeBindingPath should be aware of empty paths
Do not allow overwriting of controllers proxy properties

It was possible to accidentally set the value of `controllers.foo`, where
foo is a container-retrieved controller value as specified using `needs`.

There is no case where a developer would want to do this on purpose, and
it can cause confusion. This commit throws an error when this occurs.
render helper with context, now creates the controller
with its model, rather than setting the model post creation.

Setting the context post creating causes unneeded and wasteful change events.

@hjdivad & @stefanpenner
Merge pull request #3871 from lukemelia/read-only-needs

Do not allow overwriting of controllers proxy properties
remove Ember.alias as it has been deprecated since 2013-01-08
Merge pull request #3880 from stefanpenner/remove-ember-alias

remove Ember.alias as it has been deprecated since 2013-01-08
Merge pull request #3878 from stefanpenner/fix-render-helper

render helper with context, now creates the controller
Optimizes `{{#unbound if}}` and `{{#unbound unless}}`.

They no longer create useless metamorph views and generally execute
less code. There is no public API change here, just optimization.

Props to @machty for the review and help.
Merge pull request #3881 from lukemelia/unboundif

Optimizes `{{#unbound if}}` and `{{#unbound unless}}`.