disable fastboot with unified serving

#356 unifies fastboot serving. Apps having ember-cli-fastboot in their package.json will get fastboot render with ember 2.12 or later when pointing browser to http://locahost:4200.

It would be great to provide some options to get non fastboot render.

Usecases:

• i see some issue in fastboot version and want to check if i see the same on regular version
• i’ve started fastboot adoption, but it’s work in progress so i still want to default to non fastboot version for any feature work
• browser vs node.js dev experience - debugging

Current options, and it’s limitations:

• remove ember-cli-fastboot from package.json. Issues:
  • requires restart
  • if code uses service:fastboot we get Attempting to inject an unknown injection: 'service:fastboot'
• set FASTBOOT_DISABLED=TRUE Issues:
  • requires restart
  • currently it’s half baked as does disable package.json generation, but doesn’t disable fastboot serving, which results in Couldn't find package.json error from EmberApp.readPackageJSON

See: https://github.com/ember-fastboot/ember-cli-fastboot/pull/356#issuecomment-281784396

[kratiahuja]

@stefanpenner +1 to both

[kratiahuja]

I will address this once #356 lands.