Enable hotbar blocks

Is still slow but the format is correct now :D
Add block icons and block icon renderer

Add a block icon renderer
The block icons are listed by block ID, for ease of reference

list.lua is used to scan and generate a table out of the block files
main.lua (love2d) generates the textures

Yeah, i know its a bit funky but i wanted consistant results.
Duplicated code is bad ...

Do block processing in one pass ...