Allow to use custom "canalized" calico cni

- Allow to overwrite calico cni binaries copied from hyperkube
  by the custom ones.
- Fix calico-ipam deployment (it had wrong source in rsync)
- Make copy from hyperkube idempotent (use rsync instead of cp)
- Remove some orphaned comments

roles/network_plugin/calico/defaults/main.yml

@@ -5,5 +5,6 @@ nat_outgoing: true
 # Use IP-over-IP encapsulation across hosts
 ipip: false
 
-# cloud_provider can only be set to 'gce' or 'aws'
-# cloud_provider:
+# Set to true if you want your calico cni binaries to overwrite the
+# ones from hyperkube while leaving other cni plugins intact.
+overwrite_hyperkube_cni: false