Move buffer building out of the event loop.
Merge pull request #74 from eddyb/fps-counter

FPS counter.
Update to latest piston and gfx-rs
Use X to turn on/off extrapolation
Use Z to toggle update camera on render
Fixed bug in extrapolated time
Fixed indention + use 60 FPS
Upgraded to latest Piston
Removed X/Z
Minor fixes

* Removed unneeded trailing comma
* Removed unused `Update`
Merge pull request #75 from bvssvni/master

Update to latest piston and gfx-rs
minecraft: NBT decoding.
minecraft: implement simple loading of Anvil region files and chunk columns.
minecraft: dump biome and block state data from 1.8-pre1.
texture: add ColorMap, that maps 2D byte coords to colors from a 256x256 triangle.
minecraft: biome grass/foliage color loading.
texture: add a progressive AtlasBuilder for fixed-size textures.
minecraft: block state and model loading.
Render minecraft chunks.
minecraft: handle tall_grass' random offset.