added some safeguards for the mail to community members/conference

participants: to wit, any user can opt-out from ALL those mailings with one
setting; each message now carries a standard disKlaimer indicating how the
user can opt-out (and it's REAL opt-out, not this fakey stuff the spammers do)

src/com/silverwrist/util/OptionSet.java

@@ -257,4 +257,17 @@ public class OptionSet extends BitSet
 
   } // end asString
 
+  /*--------------------------------------------------------------------------------
+   * External static operations
+   *--------------------------------------------------------------------------------
+   */
+
+  public static final char getOptionChar(int index)
+  {
+    if ((index<0) || (index>=ALPHA.length()))
+      throw new IndexOutOfBoundsException();
+    return ALPHA.charAt(index);
+
+  } // end getOptionChar
+
 } // end class OptionSet