Unsigned plugin

[zerolaser]

I tried installing signalfx data source but it was complaining about unsigned plugin. As a work around i had to change to do the following:

• Alternatively you can run grafana in dev mode by setting GF_DEFAULT_APP_MODE to development.
  OR

• -e "GF_PLUGINS_ALLOW_LOADING_UNSIGNED_PLUGINS=signalfx-datasource"

Why is this needed:

1. Readme or Documentation needs to be updated to help users by pass this.
2. Any plans on adding community license ?
3. Will this become an enterprise plugin ?