Bugs/missing features

* Frustum culler doesn't work correctly, even though I tried
  to copy it from Minecraft java version.
  NOTE: Culling of chunks works, but entities isn't 100%

* Basically whole Item/ItemInstance package is missing
Update: Over half package is now done, but difficult to go very much
further without having items to "test"/evaluate it with.

* Lighting's broken

* Android version doesn't quit correctly. Right now it seg-faults
  on purpose, since it doesn't shut down fully if not.
  NOTE: much better now, and doesn't use segfault. Still a call to
  gl* is made with no context. Back button shouldn't actually shut
  down the process but rather hides it.

* A few (~3) "static" memory leaks (marked in the code with @memleak)

* Water horizon doesn't care about "movement head offsetting"

( * Returning some temporary AABBs by ref, not sure it's a problem.)

( * Some seeds constants are too big for long (int) data type.)

FIXED:
* Flickering. Removing glClear( color-bit ) "fixes" this.
  NOTE: div by 0.0f in bobHurt when a = 0. Java code also have this
  problem but rotating NaN or INF degrees seems fine there (or a != 0)

* Can't walk without hopping every tile or falling through tiles
  NOTE: Still jumps out of water as a feature :)

* Tile ticking, water flow and leaf decay

* Rendering business. Right now it's hardcoded to render the
  first N chunks it encounters and then no more.
  (Addon: then it might crash :p )
  And since it doesn't redraw chunks correctly, destroying tiles
  isn't graphically visible (if all N chunks have been used).
  NOTE: Now using basically the same rendering pipeline as display lists.

* Code doesn't really support playing on the network game "host" at the moment.
  NOTE: Chose a fairly straightforward approach where you let people join
  your world.

* Abyss

* (Render) Chunks are sometimes missing. Came when ChunkCache was
  rewritten/updated for fixed worlds.
  NOTE: Fixed, this and chunks not updated in multiplayer if chunk not
  visible to player were same problem (Chunk::rebuild,if(!visible)return;)
