Add (experimental) support for topbottom as well as sidebyside 3d mode

This reverts commit 649dca4d.

Fix forgotten material properties for meshes (also seems to have been forgotten for cubes previously). This allows transparent png images to work properly

RealBadAngel's patch which allows the lua api to read pressed player keys. This should make it possible to change the player's animation based on what he is doing

Correct lua api version number

Always update animations and attachments after the entity is added to scene client side. Fixes animations not being applied in client initialization for some reason. Attachments should be re-tested now just to be safe.

Fix a segmentation fault caused by reaching materials that didn't exist in a loop for setting texture

No longer hide players who are dead. With models, a death animation should be used instead

Some changes requested by celeron55

Rename a lot of things in the code, and use better lua api function names

Minor code corrections

Bump protocol version up, since the models / animations / attachments code creates new client<->server messages

Initialize m_bone_posrot too

Update pos_translator for attached players, which should fix a bug noticed with carts where a detached player would travel from the detachment spot to where it was detached

Don't make attachments possible to right-click either

Properly apply object and text visibility for local attachments, and fix them showing when they shouldn't

Fix more things I forgot for attached players. Such players will now properly see themselves moving when attached, and the server will read their position accordingly

Fix attached players being able to bob their view and generate foostep sounds by pressing a movement key (running in place)

Update attachments at the ending of the addToScene function for parents. And with this... *drum roll* Client-side attachments are at last functional and stick visibly.

Fix the last segmentation fault (apparently). So far attachments seem to be fully functional, although removing the parent causes children to go to origin 0,0,0 and possibly still cause such a fault (though this should already be addressed)

Fix a bug in falling code where entities get stuck

Also check if the parent has been removed server-side, and detach the child if so. Fixes children going to origin 0,0,0 when their parent is removed.

Unset all attachment properties when permanently detaching (on both the client and server). Also store less data we don't need

Create a separate function for detaching, and also update lua api documentation

When a child is detached, update its position from the server to clients. This WILL cause it to get positioned slightly differently client side, as the server attachment system only copies parent origin and knows not about mesh / bone transformation. This prevents different clients seeing the object detached in different spots which is most correct

Update the position of attached players to clients. An attached player will see himself move, but this is currently VERY ugly and laggy as it is done by the server (it probably must stay this way too)

Use a different approach for locally attached players. This allows for smooth positio transitions to work, as well at the player turning around freely. Still buggy however

Send animations, bone overrides and attachments in entity initialization. Clients no longer have to be near an object when an animation or attachment is set to see the changes, and newly connected clients (or a client that simply renders the object for the first time) will get all of those settings. Therefore, the lua script no longer needs to run every X seconds either, just once per entity.

Finish fixing the material color code. But it won't work until MineTest has dynamic lighting... another day another feature.

Extra checks for the bone positioning / rotation code

Many checks and consistency improvements to the client attachment code

Make a separate function for checking if a client object is attached. A more in-depth change will be needed here to fix reading of invalid pointers

Use a different method of fetching the parent. Fixes the mass segmentation faults when rendering an attachment (some still happen though)

Major change to how attachments are handled. Fix the last segmentaton fault, which was due to the parent becoming invalid while being refreshed / removed which would bause the child to remain attached to nothing. Parents remove their children when being deleted themselves and add them back when re-added. Attachments are stored inside a 2D a vector which easily allows both a child to find their parent and a parent to find its children.

Remove attachment list entry when an object is being permanently removed. Also avoid duplicate entries in this list when re-attaching the same object

The "big code comments" can now go away. Client attachments almost work properly, and I know what else needs to be done