Macro lumen_plugin 

macro_rules! lumen_plugin {
    ($ctor:expr) => { ... };
}

Export a RuntimePlugin from a cdylib crate.

Takes an expression that constructs the plugin; it runs once, when the engine initializes the module:

lumen_plugin::lumen_plugin!(MyPlugin::default);

The plugin crate must keep the default panic = "unwind"; see [init_entry] for why.