Minor transparency update

Added a few missing transparency entries, levers, trapdoors, and the brewing stand.
Update to go along with new minecraft.yml

Added placeholder stained glass textures, slime block, and a primed TNT
texture.
Merge pull request #485
Submodule pymclevel updated.

Submodule pymclevel:
    > 8309094 - Revert pull request #154
    > 1fac4de - Debug: Block YAML parsing errors are now fatal.
    > 8d48efa - Update minecraft.yaml
    > 681d94b - Best update ever!
    > be3abc9 - Absolutely perfect update for 0.8.0