Ensure $note->getModified() never returns 1969, add getCleanTitle()

lib/Note.lib.php

@@ -167,12 +167,21 @@ class Note {
         return $title;
     }
 
+    public function getCleanTitle(): string {
+        $title = $this->getTitle();
+        $title = str_replace("*", "", $title);
+        $title = str_replace("#", "", $title);
+        $title = str_replace("_", "", $title);
+        $title = str_replace("`", "", $title);
+        return trim($title);
+    }
+
     /**
      * Get the last modified date/time as "Y-m-d H:i:s"
      * @return string
      */
     public function getModified(): string {
-        if (empty($this->modified)) {
+        if (empty($this->modified) || strtotime($this->modified) == 0) {
             return date("Y-m-d H:i:s");
         }
         return date("Y-m-d H:i:s", strtotime($this->modified));