KeepNote Extensions

Additional extensions for KeepNote organizer. The package includes:
* Import Basket: Primitive import of Basket Notepad Databases.
* Import Folder Tree: Imports a folder tree as nodes in a notebook
* Import NoteCase: Primitive import of NoteCase .ncd Files
* Import Plain Text: Imports plain text files as nodes in a notebook
* Make File Catalog: Imports a folder tree, listing file names (maybe as links) notebook.