Demo 0.71 Update, New Cantrip, misc changes.

Demo 0.71 Update, New Cantrip, misc changes. - Added 'Splicer' cantrip to stronghold. - Adjusted cantrip locations. - Removed throwing axes from weapons chest (for now). - Fixed pathing issue in cellar - Removed grease repel treasure from loot table due to crash. - Renamed durability to Essence & added extra tooltip. - Lowered zombie health in early rounds. - Lowered zombie speeds in early rounds. - First skeleton now present in round 3 instead of 2. - Fixed essence/durability pickups collision issue.