Simplify code for copying to clipboard

Honestly I don't understand the old code, but it breaks on fields with
applied transformations, while using simply text() works fine.

Signed-off-by: Michal Čihař <michal@cihar.com>

js/sql.js

@@ -261,21 +261,21 @@ AJAX.registerOnload('sql.js', function () {
         textArea.value += '\n';
 
         $('.notice,.success').each(function(){
-            textArea.value += $(this).clone().children().remove().end().text() + '\n\n';
+            textArea.value += $(this).text() + '\n\n';
         });
 
         $('.sql pre').each(function() {
             textArea.value += $(this).text() + '\n\n';
         });
 
         $('.table_results .column_heading a').each(function() {
-            textArea.value += $(this).clone().children().remove().end().text() + '\t';
+            textArea.value += $(this).text() + '\t';
         });
 
         textArea.value += '\n';
         $('.table_results tbody tr').each(function() {
             $(this).find('.data span').each(function(){
-                textArea.value += $(this).clone().children().remove().end().text() + '\t';
+                textArea.value += $(this).text() + '\t';
             });
             textArea.value += '\n';
         });