Syncing HEAD back with DRUPAL-6--1 after CVS mistake.

Port to Drupal 5 and various tiny fixes

Changed to dependency to 'full' Shadowbox distrubution and how using compressed files.

Update date in CHANGELOG.txt

Improved Doxygen comments and cleaning of variable table on uninstall.

Improvement to INSTALL.txt contributed by cippo

Updating README.txt

Added most available options, help documentation and input validation.

Adding new txt files.

Improved docs by wrapping lines at 80 and abstracting relevant sections into INSTALL.txt and CHANGELOG.txt.

Initial commit of Shadowbox module. This module is a wrapper for the Shadowbox modal media viewer application, it provides functionality similar to lightbox and thickbox.