No longer CC a user by default

Its annoying to CC a user on every change they make through the web
interface, if they performed the change then they know they did it
and don't need a carbon-copy cluttering up their inbox.

Add a user level preference setting to control whether or not we
should CC the user if we are sending an email on their behalf.
By default disable it, because this is a common complaint.

Bug: issue 311
Change-Id: I431cc0e5df34ef44114bf3e5c92c4f2d5e3f0354
Signed-off-by: Shawn O. Pearce <sop@google.com>

gerrit-server/src/main/java/com/google/gerrit/server/mail/EmailHeader.java

@@ -19,6 +19,7 @@ import java.io.UnsupportedEncodingException;
 import java.io.Writer;
 import java.text.SimpleDateFormat;
 import java.util.ArrayList;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
 
@@ -118,6 +119,14 @@ abstract class EmailHeader {
       list.add(addr);
     }
 
+    void remove(java.lang.String email) {
+      for (Iterator<Address> i = list.iterator(); i.hasNext();) {
+        if (i.next().email.equals(email)) {
+          i.remove();
+        }
+      }
+    }
+
     @Override
     boolean isEmpty() {
       return list.isEmpty();