Re-export character.b3d without texture linkage.

Re-export character.b3d without texture linkage.

I've created a modified B3Dexport.py version that automatically strips
the embedded texture link to external texture files. These links were
causing the engine to spew "can't find character.png" messages on the
console, but were harmless due to texture loading being done by the
client side and not through irrlicht.

I previously moved character.png to /textures/, which is wrong. I now
understand that character.png was in the same folder as character.blend
simply to make blender load the texture from the embedded linkage
automatically. Nothing more, nothing less.

Subsequently the character.png file should just sit in convenience
in the /models/ folder with the blend file, and not in the textures
file. This patch moves it back. And yes, minetest does load the
character.png from this path.