Remove more localized exception messages.

I also accidentally mixed two unrelated changes in here: replacing "".equals
and equals("") with String.isEmpty, and removing some dead code in
org.apache.harmony.luni.util.Util.

Change-Id: I0aaad43290b083085b3095b624caf096de487223
diff --git a/xml/src/main/java/org/kxml2/io/KXmlParser.java b/xml/src/main/java/org/kxml2/io/KXmlParser.java
index 66e7fb2..dd73f0b 100644
--- a/xml/src/main/java/org/kxml2/io/KXmlParser.java
+++ b/xml/src/main/java/org/kxml2/io/KXmlParser.java
@@ -163,7 +163,7 @@
                 nspStack[j] = attrName;
                 nspStack[j + 1] = attributes[i + 3];
 
-                if (attrName != null && attributes[i + 3].equals(""))
+                if (attrName != null && attributes[i + 3].isEmpty())
                     error("illegal empty namespace");
 
                 //  prefixMap = new PrefixMap (prefixMap, attrName, attr.getValue ());