The submodule is called addthis_displays and the folder was called
addthis_display without the s at the and. Now the folder has the
correct name.

I added two alter hooks. On is to alter the markup that is used to do stuff with
the render array. The other is to alter the options that are used to help in
rendering the markup for example entity, url and display settings.

I also added a #addthis_service to the render array that is support information
for alter implementations that want to do stuff with specific service elements.

Changed some references to class constants to a syntax supported by PHP 5.2 (http://php.net/manual/en/language.oop5.constants.php). Referencing class constants via variable does not work with PHP5.2.

The Basic Toolbox display is now working in a raw form. It should be
polished by the community.