Fractal demo: Added configuration UI for load balancer IP address

Updated user_data to support converting 'list' typed parameters to/from comma separated strings.
Tweaked .gitignore to re-include lib/ directory.
Added HTML hover text to show the configured load balancer IP address.
refactor (DRY) to use _get_lb_servers() everywhere
Merge pull request #12 from GoogleCloudPlatform/fractal-config

Fractal demo: Added configuration UI for load balancer IP address
upgrade demo suite to use gce v1beta16 api
done testing so reset app version to default value (1)
Merge pull request #13 from GoogleCloudPlatform/v1beta16

V1beta16
Merge branch 'master' of https://github.com/GoogleCloudPlatform/compute-appengine-demo-suite-python into noext
per Brian Dorsey's feedback, move network config logic out of the google_cloud
lib code and have the client code select the desired network config via the
already supported network_interfaces parameter to the Instance() constructor.
This makes a lot more sense than embedding demo-specific knowledge in the
general library code.