Rewrite hologram renderer using VBOs for better performance (issue #259)
Now it really works. Need to read documentation more carefully. (#259)
Compact hologram update code (decrease Java overhead).
Also remove `dirty=true` on NBT read since privateBuf caching already takes care of it. (I hope so)
That is, d99bc5815c680198dfa7cd94eede40e5b4e66296 no longer affects hologram performance.
Mimic screen text fading for holograms.
Performance might be affected (definitely improved but I can't notice it)
Fix "reverse" color component order for holograms. It is 0xRRGGBB again.
Reenable hologram lighting
Merge branch 'VBO_hologram' of https://github.com/evg-zhabotinsky/OpenComputers

Conflicts:
	src/main/resources/reference.conf
	src/main/scala/li/cil/oc/client/renderer/tileentity/HologramRenderer.scala
Refactored the hologram renderer a bit (split phases into separate functions - init [create common buffer], validate [check if dirty, rebuild as needed] and publish [do the actual rendering]).
Also caching the buffer used for the color data and indexes to avoid spamming the GC with instances of those (can't hurt, right?)
Swapping hologram color byte order back to normal in save files for backwards compatibility.
Merge branch 'master' of github.com:MightyPirates/OpenComputers