Mk2 Expansion 1.8.6

-New Part: 'Corgi' Vacuum rocket Engine
-New Part: 'Trident' Rocket Engine
-New Part: Mk2 Bicoupler
-Part Rework: ESTOC
-Part Rework: MATTOCK
-Hypersonic cockpit IVA tweaks
-Fixes Tweakscale error on Mk2 Endcap
-Fixes TweakScale warning on Root Chines
-Removes extraneous :FOR MM syntax
-Aerospike mass, thrust reduced
-ESTOC Isp reduced to 310
-Adds B9PS tank type localization
-Mk1 Chines now properly configed for FAR
-All Mk2 parts now have proper Crash Tolerance/MaxTemp/BreakingForce values
-Adds optional 4 seat lab MM patch