fixed uv export

changed vertex by face index array.. instead of the original one, overwrite it with one with the form: 0 1 2, 3 4 5.. with no repetitions. this replication allows  the use of different uvcoords in each vertex, despite the fact the vertex is shared between different faces. 
![blender gameplay 3 20130705](https://f.cloud.github.com/assets/2874200/757285/a37e41a4-e682-11e2-9239-e4feee1ae50e.png)