Rigel 1.8.0

* Add mining support for the following coins (dev fee 1%):
  * Ravencoin (`-a ravencoin`, see `rvn` bat/sh script)
  * Neurai (`-a neurai`, see `xna` bat/sh script)
  * Clore (`-a clore`, see `clore` bat/sh script)
* (IronFish) Minor performance improvements for `<algo>+ironfish` dual modes