ca+tools: configurable ca forwarding hint and ca-server interface improvement

Change-Id: I95cc6b2fb195f7c3625f14a4f8856abcf65022d9
diff --git a/ca.conf.sample b/ca.conf.sample
index 003da8e..393cd4a 100644
--- a/ca.conf.sample
+++ b/ca.conf.sample
@@ -19,7 +19,9 @@
   "redirect-to": [
     {
       "ca-prefix": "/ndn/edu/ucla",
-      "certificate": "Bv0BNQcwCANuZG4IA2VkdQgEdWNsYQgDS0VZCAgAdGt6D7S2VAgEc2VsZggJ/QAAAX5lZMOiFAkYAQIZBAA27oAVWzBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABOKmvwHmK5t+MhMPgft4qmKC7YF9I6UM/o7GFa4BjZQknsqLvxdW2zIAF+iPPHJV0eVAijX6bYrQobuomiWZAY0WUBsBAxwhBx8IA25kbggDZWR1CAR1Y2xhCANLRVkICAB0a3oPtLZU/QD9Jv0A/g8xOTcwMDEwMVQwMDAwMDD9AP8PMjA0MjAxMTJUMDAxNjQ5F0cwRQIgBF/HS0j1DMo/dIILv/6IMUmMAhVtS3m97YgS8tsBhC0CIQCgEm0e6KoBCyV6PiueN9YW9zSSkdg8MLCxsyduP8tRsQ=="
+      "certificate": "Bv0BNQcwCANuZG4IA2VkdQgEdWNsYQgDS0VZCAgAdGt6D7S2VAgEc2VsZggJ/QAAAX5lZMOiFAkYAQIZBAA27oAVWzBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABOKmvwHmK5t+MhMPgft4qmKC7YF9I6UM/o7GFa4BjZQknsqLvxdW2zIAF+iPPHJV0eVAijX6bYrQobuomiWZAY0WUBsBAxwhBx8IA25kbggDZWR1CAR1Y2xhCANLRVkICAB0a3oPtLZU/QD9Jv0A/g8xOTcwMDEwMVQwMDAwMDD9AP8PMjA0MjAxMTJUMDAxNjQ5F0cwRQIgBF/HS0j1DMo/dIILv/6IMUmMAhVtS3m97YgS8tsBhC0CIQCgEm0e6KoBCyV6PiueN9YW9zSSkdg8MLCxsyduP8tRsQ==",
+      "policy-type": "email",
+      "policy-param": "g.ucla.edu"
     },
     {
       "ca-prefix": "/ndn/edu/ucla/cs",