support vanilla OAuth login when deploying a UI on a stand alone OpenShift cluster

[jstrachan]

e.g. right now the fabric8-runtime-console uses vanilla OAuth via angular2-oauth2 along with a blob of JSON loaded on startup:
https://github.com/fabric8-ui/fabric8-runtime-console/blob/master/src/config/oauth.json#L2

Note that we should switch that to use webpack based env var stuff though!

If ngx-login-client could support a vanilla OAuth login option (where you can pass in the auth URI, scope, issuer, client id etc) then we can refactor fabric8-runtime-console to use ngx-login-client