Add documentation to cover the `{{each}}` helper's `emptyViewClass` option.
Merge pull request #2991 from bradfol/each-empty-docs

Add docs for `{{each}}`
Fixed small typo

Fixed a small typo rturns >> returns
Merge pull request #2992 from kiwiupover/patch-1

Fixed small typo
Fix typo in core_object.js
Merge pull request #2995 from zeppelin/patch-1

Fix typo in core_object.js
update basic tests

- add handleURL helper
- handleURL helper brings its own runloop
- assert handleURL is either fulfilled or rejected
- handle previously un-handled handleURL promise rejections
remove un-needed context preservation
improve test error messages