html.class.php: Generate HTML document tags programatically

This is a simple class to compose and output HTML document by calling functions of the class to define the document HTML tags.

The details of the HTML tags are passed as parameters of the class functions.

The class provides functions to define HTML tags for the most common purposes, such as:

- Paragraphs
- Text formatting
- Tables
- Links
- Forms
- Images
- Frames
- Document structure and meta information