Update to Bootstrap v4.3.1, jQuery 3.4.1. Adjustments to support updates.

cliplist.php

@@ -136,7 +136,8 @@ echo "}\n";
 echo "</script>";
 
 // keyboard shortcut bindings
-echo "<script language='JavaScript' type='text/javascript' src='".PROJECT_PATH."/resources/jquery/jquery-1.12.4.js'></script>\n";
+echo "<script language='JavaScript' type='text/javascript' src='".PROJECT_PATH."/resources/jquery/jquery-3.4.1.min.js'></script>\n";
+echo "<script src='https://code.jquery.com/jquery-migrate-3.1.0.js'></script>\n";
 
 //save file
 key_press('ctrl+s', 'down', 'window', null, null, "if (parent.document.getElementById('frm_edit')) { parent.$('form#frm_edit').submit(); return false; }", true);

filelist.php

@@ -237,7 +237,8 @@ echo "}\n";
 echo "</SCRIPT>";
 
 // keyboard shortcut bindings
-echo "<script language='JavaScript' type='text/javascript' src='".PROJECT_PATH."/resources/jquery/jquery-1.12.4.js'></script>\n";
+echo "<script language='JavaScript' type='text/javascript' src='".PROJECT_PATH."/resources/jquery/jquery-3.4.1.min.js'></script>\n";
+echo "<script src='https://code.jquery.com/jquery-migrate-3.1.0.js'></script>\n";
 
 //save file
 key_press('ctrl+s', 'down', 'window', null, null, "parent.$('form#frm_edit').submit(); return false;", true);

index.php

@@ -97,7 +97,8 @@
 	<meta http-equiv='Content-Type' content='text/html; charset=UTF-8' />
 	<title><?php echo $title; ?></title>
 	<link rel="icon" type="image/x-icon" href="<?php echo $favicon; ?>">
-	<script language="JavaScript" type="text/javascript" src="<?php echo PROJECT_PATH; ?>/resources/jquery/jquery-1.12.4.js"></script>
+	<script language="JavaScript" type="text/javascript" src="<?php echo PROJECT_PATH; ?>/resources/jquery/jquery-3.4.1.min.js"></script>
+	<script src='https://code.jquery.com/jquery-migrate-3.1.0.js'></script>
 	<script language="JavaScript" type="text/javascript">
 		function submit_check() {
 			if (document.getElementById('filepath').value != '') {