Plugins that have the capability flag HWPLUG_CAPS_REQUIRE set can be used to hook
your plugin into the @REQUIRE preprocessor command, i.e. your plugin will be
called whenever the user runs @REQUIRE on your plugin. Hooking into the
@REQUIRE preprocessor command is mandatory for certain plugin types that are
not activated automatically when Hollywood loads the plugin. File or display adapter plugins, for
example, are only initialized once your plugin explicitly calls hw_AddLoaderAdapter()
or hw_SetDisplayAdapter() on them. This is usually done
in the RequirePlugin() function of your plugin.
See Auto and manual plugin initialization for details.
This plugin type is supported since Hollywood 6.0.