We use composer already to install SabreDAV. Include config
composer.(json|lock) to install and manage more dependencies
in future.
Also provide PSR-4 autoloading for our namespaced classes, e.g.
"Zotlabs\". To regenerate autoloader maps use:
$ composer install --optimize-autoloader --no-dev
We could also remove the whole vendor/ folder from our repository, but
that would need changes in deployment and how to install hubs and needs
more discussion first.
