Finds all strings that matches the searched value in each grid cells.
@private
function() {
         var me = this,
             count = 0;

         me.view.refresh();
         // reset the statusbar
         me.statusBar.setStatus({
             text: me.defaultStatusText,
             iconCls: ''
         });

         me.searchValue = me.getSearchValue();
         me.indexes = [];
         me.currentIndex = null;

         if (me.searchValue !== null) {
             me.searchRegExp = new RegExp(me.searchValue, 'g' + (me.caseSensitive ? '' : 'i'));
             
             
             me.store.each(function(record, idx) {
                 var td = Ext.fly(me.view.getNode(idx)).down('td'),
                     cell, matches, cellHTML;
                 while(td) {
                     cell = td.down('.x-grid-cell-inner');
                     matches = cell.dom.innerHTML.match(me.tagsRe);
                     cellHTML = cell.dom.innerHTML.replace(me.tagsRe, me.tagsProtect);
                     
                     // populate indexes array, set currentIndex, and replace wrap matched string in a span
                     cellHTML = cellHTML.replace(me.searchRegExp, function(m) {
                        count += 1;
                        if (Ext.Array.indexOf(me.indexes, idx) === -1) {
                            me.indexes.push(idx);
                        }
                        if (me.currentIndex === null) {
                            me.currentIndex = idx;
                        }
                        return '<span class="' + me.matchCls + '">' + m + '</span>';
                     });
                     // restore protected tags
                     Ext.each(matches, function(match) {
                        cellHTML = cellHTML.replace(me.tagsProtect, match); 
                     });
                     // update cell html
                     cell.dom.innerHTML = cellHTML;
                     td = td.next();
                 }
             }, me);

             // results found
             if (me.currentIndex !== null) {
                 me.getSelectionModel().select(me.currentIndex);
                 me.statusBar.setStatus({
                     text: count + ' matche(s) found.',
                     iconCls: 'x-status-valid'
                 });
             }
         }

         // no results found
         if (me.currentIndex === null) {
             me.getSelectionModel().deselectAll();
         }

         // force textfield focus
         me.textField.focus();
     }