You don't need to worry about the contents of this directory - just use emoji.php,
emoji.css and emoji.png in the parent directory.
The scripts in this directory allow you to build the library from the unicode.org source materials and the images from the gemoji project.
The main catalog contains an array of Emoji, each record containing the different codepoints, names, etc. The CSS catalog contains a mapping of codepoints to positions within the spritesheet image.
We use these intermediate mappings to create the end-user PHP and CSS files.
To rebuild the catalog from the original data tables:
wget http://www.unicode.org/~scherer/emoji4unicode/snapshot/full.html
patch < source_html.patch
php parse.php full.html > catalog.php
To rebuild the spritesheet image and its catalog, from the gemoji source files (this step requires ImageMagick or GraphicsMagick for the compositing):
php build_image.php
You can then use the catalogs to build the PHP map and the CSS file:
php build_map.php > ../emoji.php
php build_css.php > ../emoji.css
php build_table.php > ../table.htm