Mattock longsword balance changes

Remove old assets so they don't get packaged into builds

Fix smeltery gui crashing when hovering over the tank in an empty sme…

…ltery

Update version to 2.1.0 and update requirements

Version bump to 2.0.2 and requires mantle 0.7

Merge pull request SlimeKnights#1773 from Mazdallier/patch-1

Update fr_FR.lang

Fix possible NPE when calculating knockback.

Closes SlimeKnights#1731

Bump version to 1.8.6b

Bump Version. 1.8.5 Release yaaaaay!

Add nether smeltery blocks to buildcraft facades SlimeKnights#1491