Enables the loading of WordPress plugins sitting in mu-plugins (as folders)

For more information about this plugin, read this blog post: https://richardtape.com/2014/08/22/composer-and-wordpress-mu-plugins/

The original code is located in this Gist: https://gist.github.com/richardtape/05c70849e949a5017147

Because of the way Composer works, this plugin has to be installed manually. It is for this reason, also, that this plugin has its Composer vendor directory stored in the repository.

To install:

1. Copy the file muplugins-subdir-loader.php into your WordPress mu-plugins folder.
2. Copy the muplugins-subdir-loader__vendor folder into your WordPress mu-plugins folder.
3. The plugin will auto-activate.

Note: The Composer vendor directory has been renamed to muplugins-subdir-loader__vendor. This is to avoid any name collisions with anything else.