WL-1026 : A msg is public if it is public or its site is

Announcements made on a .anon site should be public by default.

Actually the code uses reverse logic : a msg is not public if it is not in a public site and it is not public

WL-1026 : doing a security check on channel

WL-1026 : Remove unused import

WL-1026 : Do security check in BaseMessage [message-util].

WL-1026 : Use reference for channel rather than depending on Site API.

WL-1026 : use m_userDirectoryService instance instead of static class
Merge pull request #1 from ox-it/WL-1026

WL-1026 : A msg is public if it is public or its site is