minerdream/md_technic

##MD Technic Extend the idea of special ores.

The standard furnace is redefined to burn only items with low burning time.

For slow melting items a new node 'smelter' is defined. It uses clay bricks as renewable refractory. With this refractory the smelter achieve higher temperatures, so it can smelt more metals in a shorter time. The smelter has a new input field for refractory, where you should place clay bricks.