Fixes and a New Feature

I've added an "End Scene" button. This will allow you to move to the next generation if you've completed your scene with the current priestess. 

I've also added a brief tutorial on for the Heir Upgrade screen.

The algorithm to select potential heir appearances has been improved.

Additionally, I've revised the screen lock to address shortcomings in the previous implementation. It should no longer be possible to break the game by clicking a button while a function is running.

Finally, I've made some small balance changes.