Only instrument views with `instrumentDetails` defined
Merge pull request #5439 from mmun/instrument-details

Only instrument views with `instrumentDetails` defined
Renderer reuses RenderBuffer instance
Remove dead code and polyfill for containsElement.
Merge pull request #5442 from rwjblue/remove-dead-contains-code

Remove dead code and polyfill for containsElement.
micro-perf: out of 1650/1800 calls superMethod is undefined.
perf: only wrap methods that container _super in the function body

Some statistics:

50 / 122 only 40% of methods currently being superWrapped need to be.

stress app boot: superWrapper calls before: 48746 after: 21094

This seems to reduce the cost of total consumed superWrapper time by the same ratio (about 40%) but also has have a net positive impact on all functions that now don't need go through the wrapper. This allows those traces to be optimized and further inlined.

Another nice bonus, is that methods not needing to be wrapped are also now much more debuggable.
Merge pull request #5443 from stefanpenner/micro-perf

micro-perf: out of 1650/1800 calls superMethod is undefined.
[Bugfix beta] just because hasOwnProperty isn’t present doesn’t mean we shouldn’t use Object.prototype.hasOwnProperty for a consistent and absolutely correct outcome.
Merge pull request #5445 from stefanpenner/more-correct-clone

[Bugfix beta] more accurate clone when dealing with null prototype objects
Prevents arguments from leaking
Remove metamorph.js
Merge pull request #5446 from mmun/remove-metamorph

Remove metamorph.js
Merge pull request #5441 from mmun/reuse-buffer

Renderer reuses RenderBuffer instance
Merge pull request #5400 from twokul/leaking-arguments

Prevents arguments from leaking
Update Morph to latest version.

Compare view:

https://github.com/tildeio/htmlbars/compare/1a4d5985824f4df23bb6e78829e442fe368937aa...7889d3f4d2a979f8e32648c92afa033f1f32b434

This includes some perf fixes by Stef to allow Morph's constructor to be
inlineable.
Merge pull request #5448 from rwjblue/update-morph

Update Morph to latest version.
[Bugfix] improve performance of scheduleOnce/Once backburner.pushUnique:

more details: https://github.com/stefanpenner/backburner.js/commit/e33c10bbc884aec441e2f34a2d26211ff91a082d
Merge pull request #5450 from rwjblue/update-bb

Update Backburner.
[BUGFIX release] Fix minification of assets.