Applying pull request from metatechbe that improves exception message.

Patch applied on behalf of metatechbe with many thanks. This closes #15


git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1658964 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java b/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java
index 409f12e..30bae3e 100644
--- a/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java
+++ b/framework/src/main/java/org/apache/felix/framework/cache/JarContent.java
@@ -160,7 +160,7 @@
         {
             m_logger.log(
                 Logger.LOG_ERROR,
-                "JarContent: Unable to read bytes.", ex);
+                "JarContent: Unable to read bytes for file " + name + " in ZIP file " + m_file.getAbsolutePath(), ex);
             return null;
         }
         finally
@@ -543,4 +543,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}