[BUGFIX release] fixes variable argument passing to triggerEvent helper

triggerEvent takes an optional third argument, but were weren't properly
resetting argument names if you didn't pass the third argument.

Passing a scope to triggerEvent was also untested.
Disable `defeatureify` when run in `development`.

Does not change `production` builds at all, just removes the
`defeatureify` filter from running in `development` (the default)
environment.
Merge pull request #5165 from trek/fix-argument-truncation-of-triggerEvent-test-helper

[BUGFIX release] fixes variable argument passing to triggerEvent helper
[FEATURE ember-routing-auto-location-uses-replace-state-for-history] Use replaceState in AutoLocation to avoid a full redirect