Game class is too huge and has too specialization on various subjects, like UI, formspecs, client, renderer. Start to move UI related things to GameUI object and cleanup them
Other improvements:
* updateChat: more performance on error messages by remove string copies
* Initialize all game class members in definition instead of constructor (with nullptr instead of NULL)
* Drop unused Client::show{GameChat,GameHud,Profiler,GameFog}
* Add GameUI unittests
* [CSM] Don't load the IO library.
* Rename the function to match the Lua API function name and add a missing `const`
* Add a comment to explain some strange code and fix the other issues pointed out by shadowninja.
The `disconnected_*` boxes are the opposites of the `connect_*` ones,
i.e. when a node has no suitable neighbours on the respective side, the
according disconnected box is drawn.
* disconnected_top
* disconnected_bottom
* disconnected_front
* disconnected_left
* disconnected_back
* disconnected_right
* disconnected (when there is *no* neighbour)
* disconnected_sides (when there are *no* neighbours to the sides)
This still leaves plenty of data undecoded, but just having the packet
types all covered 100% for 0.4.16 will make looking at traces a lot
simpler than seeing half the packets show up as unknown.
* Add player deletion method to auth handler (fixes #6653)
* Support iterating over the auth database
There was no way to do this previously and a recent commit
broke doing this the "hacky" way by accessing `core.auth_table`.
Fixes #6676.
Allow animated meshes to be cached in Irrlicht's builtin mesh cache.
Use Material.EmmissiveColor instead of manipulating the mesh' vertex colors.
Remove player object property 'can zoom'.
Add player object property 'zoom fov'.
Remove clientside setting for 'zoom fov'.
Object property default is 15 degrees in creative mode, zoom disabled
in survival mode.
Needed due to zoom now loading and/or generating distant world
according to zoom FOV.
Update object properties serialisation version to 3.
