Tweak some textures, new chest texture

mods/default/README.txt

mods/default/textures/default_apple.png

mods/default/textures/default_chest_front.png

mods/default/textures/default_chest_lock.png

mods/default/textures/default_chest_side.png

mods/default/textures/default_chest_top.png

mods/default/textures/default_desert_stone_brick.png

mods/default/textures/default_dirt.png

mods/default/textures/default_snowball.png

mods/default/textures/heart.png