Compiled env.config.js

Nobody has claimed this yet.

Minko, I ran into an issue where the env.config.ts is being compiled into JS, and when a dev reload happens, the ENV_CONFIG value stops getting replaced. Or more specifically, the compiled JS version without the replacement seems to be getting copied over to /dist during the asset copy. So an error is thrown since `JSON.parse('<%= ENV_CONFIG %>');` is invalid.

I found an older issue #1747 which seems to be the same problem. In order to solve it, I had to modify `build.assets.dev.ts` to add:
```
'!' + join(Config.APP_SRC, '**', 'env.config.js'),
'!' + join(Config.APP_SRC, '**', 'env.config.js.map'),
```

I'm not sure why this suddenly started being a problem, but I thought I would mention it again in case the additional exclusions are something you want to include in the seed.

Start by reading build.assets.dev.ts and tracing how env.config.ts, env.config.js, and its source map are copied into /dist during dev reloads. Compare the existing asset exclusions with the issue's proposed patterns; done means the compiled files no longer overwrite the replaced configuration and the dev reload no longer throws the JSON.parse error.

Written by the indexing model from the issue text.