[DOC beta] Mark Route#render options as optional
PromiseProxies should have content or a reason when settled

Fixes #5325
Merge pull request #5327 from gavacho/master

PromiseProxies should have content or a reason when settled
Ember.copy should copy null prototype object
Merge pull request #5331 from alexBaizeau/bugFix/copyObjectWithNullPrototype

[BUGFIX] Ember.copy should copy null prototype object
[BUGFIX beta] Fix initial render of {{input type=bound}} for checkboxes
Merge pull request #5333 from amiel/fix-bound-input-type

[BUGFIX beta] Fix initial render of {{input type=boundValue}} for checkboxes
[BUGFIX beta] makeBoundHelper supports unquoted bound property options - Fixes #5245