Closes #344

Read the config from a URL rather than a local file if the name of the config file starts with "http"
#344 further update

Update per comment https://github.com/couchbase/sync_gateway/commit/3731c94262bf418ba2937b724a7f406002564840#src-github-com-couchbaselabs-sync_gateway-rest-config-go-P46
Add missing comment
Merge pull request #345 from couchbase/feature/remote_config

Allow remote config files accessed over HTTP