Make computed.sort generate an answer immediately

This is a followup to pull #9356 that gives nicer timing. It extends the
arrayComputed protocol with a `flushedChanges` callback so that
implementations like `computed.sort` can confidently do batched
operations without waiting a whole run loop.
[DOC beta] Fix typo, change 'they' to just 'the', per #9373
Merge pull request #9375 from tehcurtis/9373_fix_minor_text_support_typo

[DOC beta] Fix typo, change 'they' to just 'the', per #9373
Merge pull request #9372 from ef4/sort-timing

Make computed.sort generate an answer immediately
Cleanup Route example code
Merge pull request #9379 from knownasilya/patch-1

Cleanup Route example code
[BUGFIX beta] Add assertion when morph is not found in RenderBuffer.
Merge pull request #9377 from rwjblue/hydrate-morph-assertion

[BUGFIX beta] Add assertion when morph is not found in RenderBuffer.
[BUGFIX beta] Refactor buffer to be simpler, single parsing code-path

Add rerender blank tagName with omitted start tag tests
Log unhandled promise rejections in testing #9376
Merge pull request #9382 from kategengler/add-log-to-rsvp-test-error-handler

Log unhandled promise rejections in testing #9376
Change variable naming
[DOC beta] Fix typo, 'and and' -> 'and'
Merge pull request #9385 from tricknotes/fix-typo

[DOC] Fix typo, 'and and' -> 'and'
[BUGFIX beta] setProperties should handle non-object properties
Merge pull request #9386 from kategengler/fix-object-keys-error

Fix regression in setProperties
Merge pull request #9361 from mixonic/render-buffer

[BUGFIX beta] Refactor buffer to be simpler, single parsing code-path
[BUGFIX beta] deprecate location: 'hash' paths that don't have a forward slash. e.g. #foo vs. #/foo. Also adds much needed test coverage for HashLocation in general
Merge pull request #9388 from jayphelps/hash-location-no-slash-deprecate

[BUGFIX beta] deprecate location: 'hash' paths that don't have a forward slash. e.g. #foo vs. #/foo
[BUGFIX] HashLocation no longer assumes any hash is a route, uses forward slash prefix convention #/foo