Demo Item Bases and Other Fixes

Add 7 new base items to the game, focusing on the Beastmaster and the Arcanist

Add 16 new Nightmare Items to the game, focusing on item slots that had zero or few options

Added a new Arcanist Conjurer skill - Nature's Grace. This skill increases Physical and Poison resistance minorly

Added "+{x} Nature's Grace skill level" to offhands dropped for the Arcanist

Greatly reduced the CPU usage of Meteor. Note that this causes the shrapnel effect to explode slightly sooner in order to make this optimization possible

Fixed a bug where the Beastmaster passive would often not apply. This also fixes an issue where Avatars would not have a chance to tame minions

Fixed a bug where Cooldown Recovery on Hunting Shuriken was increasing its cooldown time, not reducing it. This is a buff, or so they say

Moderately reduced the Memory usage of Meteor

Slightly reduced the memory usage of Airship Bombardment

Reduced the iframes of Airship minions by half

Fixed a number of mis-tagged item mods

Fixed a bug where you could bulk sell Boss items