changed class instantiations to reference global $LANG and fetch existing Exceptions class, and added language variable for database error heading

http://codeigniter.com/bug_tracker/bug/4421/
diff --git a/system/language/english/db_lang.php b/system/language/english/db_lang.php
index 6c053a1..697eb78 100644
--- a/system/language/english/db_lang.php
+++ b/system/language/english/db_lang.php
@@ -21,7 +21,7 @@
 $lang['db_column_name_required'] = 'A column name is required for that operation.';

 $lang['db_column_definition_required'] = 'A column definition is required for that operation.';

 $lang['db_unable_to_set_charset'] = 'Unable to set client connection character set: %s';

+$lang['db_error_heading'] = 'A Database Error Occurred';

 

-
-/* End of file db_lang.php */
+/* End of file db_lang.php */

 /* Location: ./system/language/english/db_lang.php */
\ No newline at end of file