Adding std::forward<Args>( args )... to Signals, to allow for emitting && variables

Hey Embers,

Just thought I’d ask if anyone else might want to have signals that are able to pass && variables?

It necessitates a slight change to Signals - basically inserting std::forward<Args>( args )... wherever the args are used.

As far as I know that’s the preferred way to pass around unique_ptr’s - I was thinking perhaps I should create a pull request for the change to put it in 0.9.2.