eeshow/: Esc cancels current action

eeshow/help.html

@@ -28,6 +28,10 @@
   <TR>
     <TD>Tab
     <TD>toggle between old and new revision
+  <TR>
+    <TD>Esc
+    <TD>cancel current action (exit history, close pop-up, 
+	de-highlight glabel, close help)
   <TR>
     <TD>H
     <TD>open/close help window