Those scripts are an example on how to allow media:/ to use
hotplugging events.

1) mediamanager_usbstorage.dev
This file only needs to be copied to /etc/dev.d/default

2) usbcam
This one is a bit more complicated to install.
The file must be copied into /etc/hotplug/usb and the file
/etc/hotplug/usb/usbcam.usermap must exists (you can use
libgphoto2's print-usb-usermap command to create it)