fix logic arroudn accept/block contact and add unblock support

@@ -14,2 +14,4 @@
 }
 
+// Serialize transforms the AccessControl into json.
+func (ac *AccessControl) Serialize() []byte {

@@ -501,1 +503,4 @@
+// BlockConversation looks up a conversation by `handle` and sets the Blocked ACL field to `true`
+// This will cause Cwtch to never try to connect to and refuse connections from the peer
 func (cp *cwtchPeer) BlockConversation(id int) error {
+	return cp.setACL(id, &model.AccessControl{Blocked: true, Read: false, Append: false})

@@ -502,0 +509,4 @@
+// UnblockConversation looks up a conversation by `handle` and sets the Blocked ACL field to `true`
+// Further actions depend on the Accepted field
+func (cp *cwtchPeer) UnblockConversation(id int) error {
+	return cp.setACL(id, &model.AccessControl{Blocked: false, Read: false, Append: false})

@@ -508,1 +533,4 @@
+		return err
+	}
+
 	// p2p conversations have a single ACL referencing the remote peer. Set this to blocked...