Invocations

Invocation system simplified so that it doesn't take more than 3 runes to cast a spell. There are also no more repeats of spells. It should be much easier to cast more complicated invocations.

Runes are no longer based off of mob effects, but a separate counter that is represented visually by up to three cycling runes around the crosshair.

Spells no longer need to hit a mob to grant a rune of their respective element. Note that spells that need targets in order to finish casting still need to finish casting in order to grant a rune.

Granting of runes is now tied as a passive to the Runic Invocation spell, rather than to the basic invocation spells. This means that if you were to gain an item with the Runic Invocation spell (such as via commands), you would be able to gain runes by casting any spell via spellbook. I plan on doing something with this in the future.

Rah basic spell damage nerfed, 0.9x -> 0.75x Fire.