DEV: Allow us to use Ember CLI assets in production (PR #13906)

This adds an optional ENV variable, EMBER_CLI_PROD_ASSETS. If truthy, compiling production assets will be done via Ember CLI and will replace the assets Rails would otherwise use.


Are the two lists necessary or can they be merged? (into the reject! block?)

Out of curiosity, why do we need to encode the json string here as a URL?

That’s how Ember CLI does it and I wanted to keep the format the same.

Good catch. That previous line was my failed attempt to remove them. Only reject! is required and I’ve fixed it.