improved mountspoints and airtightness on slingers

-removed 2x LargeHeavyBlockArmorBlock damage modifier.
-disabled EMP barrel animation particle
-set DurabilityMod to .25 across the board. this on average is 2x durability buff.

Fixed menu group and blockvariant group for the slinger cannon

-Added the Slinger 150mm cannon turret, including 2 sloped variants.
-150mm ammo is now explosive.
-150mm ammo speed 650 > 750
-150mm ammo range increase. Targeting is the same the bullets just go farther.
-Gatling ammo range increase. Targeting is the same the bullets just go farther.
-Increased durability of several of the smaller turrets.

Fixed particle scale problems, keen update enabled scale to work and my setups are a mess

-T3 beam ammo set damage voxel to false

T2 PDX/Gimbals no longer target projectiles.

-Fixed mirroring for T2 PDX (mostly). The sloped variants are like 80% good, best I can do for now.

-Reduced turning speed for PDX, T2 PDX, Gimbals, T2 Gimbals
-Fixed T2 gimbal group not showing PDX variants

-fixed block category menu for the T2 stuff