[RFC] Expanding hooks API for running several scripts by one call virHookCall

Hi, all. I have the proposal about subject. Libvirt hook calls only one script (/etc/libvirt/hooks/<driver>) now. This is not convenient if scripts for hook are provided by many vendors. Script one vendor can replace previously installed script other vendor. Let's use usual linux scheme - running all scripts from directory /etc/libvirt/hooks/<driver>.d in alphabetical order. If we find script in old place we will execute it before others in subdirectory for backward compatibility. I want to implement patch for this scheme. What is your opinion? Dmitry