Generalized delegates

[alfreb]

Since #10 there's now a specialized delegate class in IRQ_handler which allows delegation of any IRQ to any member function with signature void (). This should be replaced with a generalized delegate class, possibly this one since the C++11 version relies heavily on the standard library. Alternatively, we can wait until we have the Std library.

[alfreb]

See #32

[alfreb]

They seem to work - Good job Gonzo 👍 Closing this and reporting bugs if they don't.