Unified FGD changes 2

[vrad-exe]

Ahh, ah, ahhhh

• Add white axis helper for env_sprite (env_sprite colors the axis helper but not the sprite #57)
• Fix render mode for env_beam, env_laser, npc_bullseye (env_laser iconsprite does not render transparent #70)
• Enable func_instance and func_instance_parms in all games (Instance entities are not included in all FGDs #14)
• Enable modelscale for physics props in all games (BaseEntityPhysics should have modelscale in all games #65)
• Use axis_helper_thick for move_rope (Change "move_rope" model to use the thick axis helper #54)
• Swap decal keyvalue types to material, to suppress annoying auto-filtering behavior
• Add iconsprites for some entities (List of entities with missing/duplicate iconsprites #35):
  • comp_pack_replace_soundscript
  • env_portal_credits
  • info_player_ping_detector
  • skybox_swapper
• Improve env_credits FGD, and fix inverted sprite font.
• Improve prop_weighted_cube FGD, better explaining how to use custom models and fixing "Weighted Pivot Cube" should be "Discouragement Redirection Cube" #64
• Fix incorrect Black Mesa healing shower model
• Ignore .cache (soundcache) files
• Switch every weapon ent from studio() to studioprop(), and fix weapon_bugbait and weapon_crossbow do not display models in Hammer #40
• Rename some HL2/Black Mesa global states
• Add Hammer model keyvalue to sphere buttons
• Better explain how to change pedestal/cube/sphere button models
• Add Co-op portal skins to prop_portal model (Add Co-op portal skins to prop_portal Hammer model #85), and make the starting portal color consistent between game and Hammer (prop_portal's starting portal color and Hammer skin are inconsistent #86)
• Use Ficool2's info_null icon
• Improve npc_rocket_turret FGD, adding tripwire mode keyvalues and model customization
• Add func_train entity, a mostly-obsolete Quake leftover that's useful for fast-moving objects.
• Improve env_portal_path_track FGD, basing directly on normal path_tracks and properly explaining how it differs from those.
• Make npc_wheatley_boss default to the full model, instead of the cutoff monitor one which nobody should be using.
• Improve descriptions for RunScriptCode and Init Code, explaining the backticks functionality.
• Remove text size/color keyvalues from hammer_notes in games that don't support them