[DOC beta] Assert if template for {{render}} not found.

Added an assertion if the template name provided to `{{render}}` was not
found.

Two tests were previously not working properly, and have been fixed. They registered
templates as `"blog/post"`, which is never looked up with `{{render}}` (as any
slashes in the name are translated to a period before this lookup
happens).

Resolves #3926.
[DOC beta] Fix YUIdoc method names
Merge pull request #3975 from bradleypriest/patch-1

Fix YUIdoc method names
Changes documentation for observable.setProperties to clarify that observers will be buffered. This makes it consistent with
Merge pull request #3986 from MiguelMadero/set_properties_doc

Changes documentation for observable.setProperties to clarify that observers will be buffered.
deprecate RSVP.Promise.prototype.fail
Merge pull request #3987 from fivetanley/deprecate-rsvp-fail

deprecate RSVP.Promise.prototype.fail
Get benchmarks running again, using external URLs
Merge pull request #3990 from mixonic/fix-benchmarks

Get benchmarks running again, using external URLs
Remove license comment duplication

`*.min.js` already contain license comment because uglifier keeps
license comment that marked up with `@license` tag.

This duplication is injected in #3865.
Include version to header comment

It is useful that version is kept after minify.
bundle update

To follow up emberjs/ember-dev#116 .
Merge pull request #3996 from tricknotes/include-version-to-header-comment

Include version to header comment
small computed docs fixes
Merge pull request #3997 from twokul/computed-doc-fixes

small computed docs fixes
[DOC beta] Ember.View documentation cleanup.
[DOC beta] Several doc fixes
[DOC beta] Cleanup Ember.TrackedArray docs.
Label promises for debugging
[beta] Update handlebars to 1.2.1.