Support LIGGGHTS simulations

Iota can run coarse-graining analysis for the following output DEM files generated by LIGGGHTS:

• LIGGGHTS DUMP: ASCII files generated by the dump custom, dump local and dump stl commands in the LIGGGHST simulation script. More details can be found here

• LIGGGHTS VTK: VTK files in ASCII or binary format generated by generated by the dump custom/vtk, dump local/gran/vtk and dump mesh/vtk commands in the LIGGGHST simulation script. More details can be here