Time slice in name

[Francisco Javier Díez]

Currently the names of temporal variables are no properly written:

  <Link directed="true">
    <Variable name="State [0]" timeSlice="0" />
    <Variable name="State [1]" timeSlice="1" />
  </Link>

It should say <Variable name="State" timeSlice="0" />.

The same occurs for variables inside potentials.

Surprisingly, the parser works, even though it should throw an exception.