Move from _core run.sh code specific to Docker

[baylanger]

Take "docker related" code from run.sh. There's no code currently per say BUT there's a comment :)

We need to create a function named ... validateEnvVars() ? that validates the environment variables provided by the end user via Docker env vars.

Then add the generic product's function named productInit() and inside that function, the code needs to call validateEnvVars()

Fatal errors must use fatal and exit.

In _core there's code being added to source../libproduct.sh (if available).

[baylanger]

Whenever possible, need to also move the following:

export HA_BACKEND_DISABLE=${HA_BACKEND_DISABLE:=false}

[iainbullock]

I think this is done, I will close