Optimization to non-cube blocks

Request:
Include cullface for additional models in-game
Remove terminating faces for non-cube models in-game.

Why:
Although most players and modern computers are very well able to handle Vanilla textures, any reasonable chance we have to cullface or remove faces for rendering should be explored.

How:
I've linked an example pack with a variety of cullfaces and some unrendered faces.

___

I've spent a few days looking through Minecraft's vanilla block models and found that a variety of models could benefit from either removing faces from elements that terminate inside another element, or cullfacing elements that are appear against a solid cube.

https://drive.google.com/open?id=1bxpwsdm0_-5MFgg7lNJ1vQv95wMrnOzq

Files include:

anvil.json
beacon.json
brewing_stand.json
cauldron.json
cauldron_level1.json
cauldron_level2.json
cauldron_level3.json
chorus_flower.json
comparator.json
comparator_on.json
comparator_on_subtract.json
comparator_subtract.json
end_portal_frame.json
end_portal_frame_filled.json
end_rod.json
flower_pot.json
flower_pot_cross.json
hopper.json
hopper_side.json
item_frame.json
ladder.json
lever.json
lever_on.json
potted_cactus.json
potted_fern.json
repeater_1tick.json
repeater_1tick_locked.json
repeater_1tick_on_locked.json
repeater_2tick.json
repeater_2tick_locked.json
repeater_2tick_on_locked.json
repeater_3tick.json
repeater_3tick_locked.json
repeater_3tick_on_locked.json
repeater_4tick.json
repeater_4tick_locked.json
repeater_4tick_on_locked.json
snow_height14.json
template_fence_gate.json
template_fence_gate_open.json
template_fence_gate_wall_open.json
template_glass_pane_post.json
template_glass_pane_side.json
template_glass_pane_side_alt.json
template_piston_head.json
template_torch.json
torch_wall.json
tripwire_hook.json
tripwire_hook_attached.json
tripwire_hook_attached_on.json
tripwire_hook_on.json
vine_1.json
vine_1u.json
vine_2.json
vine_2u.json
vine_2u_opposite.json
vine_2_opposite.json
vine_3.json
vine_3u.json
vine_4.json
vine_4u.json
vine_u.json

Most of these files include "cullface": "down" alongside other cullfaces  ||  If certain blocks required another block to be under them to be placed, the "down" face was removed

Noticeable face removals:

ladder, vines, instead of cullface; the face was removed.

torch_wall, very bottom of the texture in the pack is removed, but the element's down face does peak out slightly from the wall; this is generally very unnoticeable however.

~~~~~
Potential Bugs (to be reported later)

Blockstate lever.json references "lever_on" model for the unpowered lever, and "lever" for the powered lever, this isn't intuitive and seems flipped unintentionally.

snow_height14.json model; this model is the only state of snow_layer that does not include any cullfaces unlike all the other layers.


flower_pot.json + flower_pot_cross.json + potted_fern.json + potted_cactus.json
ALL reference a set of transparent pixels in #flowerpot, this causes the bottom of the model to be transparent

{ "from": [ 6, 0, 6 ],
"to": [ 10, 4, 10 ],
"faces": {
"down": { "uv": [ 6, 6, 10, 10 ], "texture": "#flowerpot", "cullface": "down" },
"up": { "uv": [ 6, 6, 10, 10 ], "texture": "#dirt" }
}
}
The down face should be: "down": { "uv": [ 6, 10, 10, 14 ]