register_plugin_directory needed

[miljushm]

Hi guys,

we have awesome function register_theme_directory which makes registering additional theme directories very flexible and I think having the same (register_plugin_directory) for plugins is something we need so bad.

I am aware of activate_plugin function but it's not flexible at all, at least not near register_theme_directory since only plugins located in the /plugins/ directory or /plugins/my-example-plugin/ can pass the validation (validate_plugin and get_plugins), otherwise it returns that plugin doesn't have good headers which is another confusion.

Cheers!
Marko

[ocean90]

Duplicate of #19721.