New normalmaps for some nodes

mods/default/textures/default_cactus_side_normal.png

mods/default/textures/default_cactus_top_normal.png

mods/default/textures/default_desert_stone_brick_normal.png

mods/default/textures/default_dirt_normal.png

mods/default/textures/default_dry_grass_normal.png

mods/default/textures/default_dry_grass_side_normal.png

mods/default/textures/default_grass_normal.png

mods/default/textures/default_grass_side_normal.png

mods/default/textures/default_jungletree_normal.png

mods/default/textures/default_jungletree_top_normal.png

mods/default/textures/default_junglewood_normal.png

mods/default/textures/default_tree_normal.png

mods/default/textures/default_tree_top_normal.png

mods/default/textures/default_wood_normal.png