Applying patch (XalanJ-2183-SqlExtension-DefConPoolFix.patch) from John Gentilin.
This patch fixes a problem with the default connection pool where we were using an
Iterator but in the Iterator look we were trying to remove elements in the Iterators's
collection. This caused a concurrent access error.
Reviewd by Yash Talwar.

diff --git a/src/org/apache/xalan/lib/sql/DefaultConnectionPool.java b/src/org/apache/xalan/lib/sql/DefaultConnectionPool.java
index ea34a6d..934e0bc 100644
--- a/src/org/apache/xalan/lib/sql/DefaultConnectionPool.java
+++ b/src/org/apache/xalan/lib/sql/DefaultConnectionPool.java
@@ -139,7 +139,7 @@
         }
         
         pcon.close();
-        m_pool.remove(pcon);
+        i.remove();        
       }
     }