IDEA-140862 Changed the "Regex" checkbox ChangeListener to ItemListener

The only change they actually need is the selection change.
Also add a mnemonic.

https://github.com/JetBrains/intellij-community/pull/540

platform/platform-resources-en/src/messages/VcsBundle.properties

@@ -466,7 +466,7 @@ outdated.version.text.deleted=Outdated version. Deleted by {0} {1}: {2}
 current.version.text={4}<br/><br/>Current version is {3}.<br/>Modified by {0}<br/>{1}<br/>{2}
 committed.changes.filter.title=Filter by
 committed.changes.group.title=Group by
-committed.changes.regex.title=Regex
+committed.changes.regex.title=Re&gex
 changelist.details.committed.format=Committed by {0} {1}
 incoming.changes.indicator.tooltip={0} incoming changelists available
 column.name.type=Type

platform/vcs-impl/src/com/intellij/openapi/vcs/changes/committed/CommittedChangesPanel.java

@@ -52,6 +52,8 @@ import javax.swing.*;
 import javax.swing.event.ChangeEvent;
 import javax.swing.event.ChangeListener;
 import java.awt.*;
+import java.awt.event.ItemEvent;
+import java.awt.event.ItemListener;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.LinkedList;
@@ -103,9 +105,10 @@ public class CommittedChangesPanel extends JPanel implements TypeSafeDataProvide
     toolbarPanel.add(Box.createHorizontalGlue());
     myRegexCheckbox = new JCheckBox(VcsBundle.message("committed.changes.regex.title"));
     myRegexCheckbox.setSelected(false);
-    myRegexCheckbox.getModel().addChangeListener(new ChangeListener() {
+    myRegexCheckbox.getModel().addItemListener(new ItemListener() {
       @Override
-      public void stateChanged(ChangeEvent e) {
+      public void itemStateChanged(ItemEvent e) {
+        // TODO: no need to re-filter if the text field is empty anyway
         myFilterComponent.filter();
       }
     });