Removed salt from unrestricted groups: two unrestricted groups with

the same name will now be treated as the same group (this seems more
intuitive than the alternative).

api/net/sf/briar/api/protocol/Group.java

@@ -1,7 +1,5 @@
 package net.sf.briar.api.protocol;
 
-import java.security.PublicKey;
-
 import net.sf.briar.api.serial.Writable;
 
 /** A group to which users may subscribe. */
@@ -13,22 +11,9 @@ public interface Group extends Writable {
 	/** Returns the group's name. */
 	String getName();
 
-	/**
-	 * Returns true if messages sent to the group must be signed with a
-	 * particular private key.
-	 */
-	boolean isRestricted();
-
-	/**
-	 * If the group is restricted, returns null. Otherwise returns a salt
-	 * value that is combined with the group's name to generate its unique
-	 * identifier.
-	 */
-	byte[] getSalt();
-
 	/**
 	 * If the group is restricted, returns the public key that is used to
 	 * authorise all messages sent to the group. Otherwise returns null.
 	 */
-	PublicKey getPublicKey();
+	byte[] getPublicKey();
 }

api/net/sf/briar/api/protocol/GroupFactory.java

@@ -2,6 +2,5 @@ package net.sf.briar.api.protocol;
 
 public interface GroupFactory {
 
-	Group createGroup(GroupId id, String name, boolean restricted,
-			byte[] saltOrKey);
+	Group createGroup(GroupId id, String name, byte[] publicKey);
 }