Correctly handle paths with URL-escaped characters

URL-unescape the path portion of a change history token to correctly
handle paths with URL-escapable characters, i.e. '+', ' ', etc.

Bug: Issue 1682
Change-Id: Iefbbb8a86062152d4227ab0a49f9fd91333af554
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/Dispatcher.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/Dispatcher.java
index c8b1e48..87a09cf 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/Dispatcher.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/Dispatcher.java
@@ -490,7 +490,7 @@
     }
 
     if (!rest.isEmpty()) {
-      Patch.Key p = new Patch.Key(ps, rest);
+      Patch.Key p = new Patch.Key(ps, KeyUtil.decode(rest));
       patch(token, base, p, 0, null, null, panel);
     } else {
       if (panel == null) {