Use networking for version 2 Compose files

- Remove --x-networking and --x-network-driver
- There's now no way to set a network driver - this will be added back
  with the 'networks' key

Signed-off-by: Aanand Prasad <aanand.prasad@gmail.com>

contrib/completion/zsh/_docker-compose

@@ -332,8 +332,6 @@ _docker-compose() {
         '(- :)'{-v,--version}'[Print version and exit]' \
         '(-f --file)'{-f,--file}'[Specify an alternate docker-compose file (default: docker-compose.yml)]:file:_files -g "*.yml"' \
         '(-p --project-name)'{-p,--project-name}'[Specify an alternate project name (default: directory name)]:project name:' \
-        '--x-networking[(EXPERIMENTAL) Use new Docker networking functionality. Requires Docker 1.9 or later.]' \
-        '--x-network-driver[(EXPERIMENTAL) Specify a network driver (default: "bridge"). Requires Docker 1.9 or later.]:Network Driver:(bridge host none overlay)' \
         '(-): :->command' \
         '(-)*:: :->option-or-argument' && ret=0