Allow bound outlet names

[ef4]

Bound outlet names actually work fine without any additional work. They
were just disallowed due to a very old assert that was introduced back
when we were first standardizing the use of quoted strings to represent
literals.

This drops the assertion and adds a test that shows bound outlet names
work.

[rwjblue]

👍

[ef4]

Sauce labs timed out.

[rwjblue]

Restarted.

[john-kurkowski]

Does this indicate a breaking change in the 1.x series? {{outlet foo}} used to be equivalent to {{outlet "foo"}}. I'm upgrading an Ember 1.8 app to 1.13 and was lucky I came across this in 1.13's changelog. It gave me a hint why some of my outlets were not rendering at all: they were unquoted and thus assumed bound to some undefined property. The assert would've saved me some time.

[ef4]

I'm pretty sure unquoted outlet names already generated a warning in 1.8, yes?

[john-kurkowski]

I hadn't noticed any warnings then. Quote-less outlet names were officially deprecated in 1.10. I wouldn't have thought that meant removal in the 1.x series though. Worth noting in the changelog? I'm not sure it's this PR per se. At the very least, hope Google leads others with the same issue to here.