fix save menu lockout when dying after medallion cast (#126)

[FitzRoyX]

flag_custom_spell_anim_active is set at the start of each medallion cast. This flag and others are checked every frame by the main controller function on whether to disable save menu access or not. This is mainly to stop you from saving and quitting in the middle of a medallion receipt cutscene.

Instead of being cleared at the end of the medallion routines, it is cleared in Graphics_LoadChrHalfSlot(), which apparently delays the clearance enough (2 frames after the cast is done) that death immediately after a medallion cast will skip this clearance.

So when you continue after dying, you're walking around with flag_custom_spell_anim_active = 1 and you can't save until casting again.