Installing composer dependencies
 We use composer to install PHP dependencies. These are defined in the
 file composer.json, the current dependency metadata is in composer.lock.
 To fetch the dependencies:
 * Get composer.phar as described at
 * run [path_to]/composer.phar install in the webroot.
 This will install all required dependencies to the directory vendor.
 The vendor directory is listed in .gitignore to avoid committing
 duplicates of upstream projects.