"Enable automatic updates" setting propagates to antitracking and adblocker

[sammacbeth]

Fixes #561

Allows all remote resource fetches from modules in ghostery-common to be disabled.

• Disabling "Enable automatic updates from the Ghostery tracker library" will also disable updates to antitracking and adblocker lists.
• Disabling humanweb will disable the hpnv2 module entirely, preventing fetches to its config endpoint.

To test, check network calls from the extension, and reload the extension to see startup calls:

• When automatic updates are enabled, there will be a call to https://cdn.ghostery.com/antitracking/whitelist/2/update.json.gz. When disabled, this call will not happen.
• When humanweb is enabled, there will be a call to https://api.ghostery.net/api/v1/config on start, and subsequent calls to https://collector-hpn.ghostery.net/config. When disabled, these calls will not happen.