Add ore blocks. Closes GH-79, closes GH-60
Merge pull request #92 from deathcap/ores

Add ore blocks. Closes GH-79, closes GH-60
Add gravel
Don't process buffers for unloaded chunks
Limit the number of build tasks sent to prevent the workers from becoming overloaded and processing unloaded chunks due to not getting the unload message in time
Add logs
Remove old todo
Add time of day brightness
Add leaves
Use server time and fix the time of day lighting going backwards
Added sponge, glass, lapis blocks, dispensers and droppers
Added sandstone and noteblocks
Rework the state system to support virtual blocks (still a bit slow) + added vines
Added beds
Manually copy section data instead of letting the browser do it.

Turns out its faster this way (At least from my tests)
Reduce the of look ups and casts in WorkerChunk
Use IntMap instead of HashMap for legacy look ups
Respond to OPTIONS and HEAD requests to /chunk
Add missing headers (Closes #91)
Fix the block texture being looked for in the wrong location