Support pods with containers using host ipc

Add a HostIPC field to the Pod Spec to create containers sharing
the same ipc of the host.

This feature must be explicitly enabled in apiserver using the
option host-ipc-sources.

Signed-off-by: Federico Simoncelli <fsimonce@redhat.com>

api/swagger-spec/v1.json

@@ -12531,6 +12531,10 @@
       "type": "boolean",
       "description": "Use the host's pid namespace. Optional: Default to false."
      },
+     "hostIPC": {
+      "type": "boolean",
+      "description": "Use the host's ipc namespace. Optional: Default to false."
+     },
      "imagePullSecrets": {
       "type": "array",
       "items": {