Detect Corpse and Summon Wisp spells

Adds 3 new spells and a lesser power.

Summon Wisp, Detect Corpse (and ash piles), Disintegrate Corpse, Fortify Speed, and Trade With Me spells and Clairvoyance as a Lesser Power. (DLC Required.)

Summon Wisp, Detect Corpse (and ash piles), Disintegrate Corpse, Fortify Speed, and Trade With Me spells and Clairvoyance as a Lesser Power. (No DLC version.)

Detect Arrows spell added. (Legendary Edition version requires Dawnguard and Dragonborn.)

Detect Arrows spell added. (This version doesn't require the DLCs but also won't detect their ash piles.)