For some reason the connectivity for collision meshes was not being
properly assigned.
Also, the first subroutine to read information from .vtu files as
initial states has been added.
It is currently giving wrong results.
First complete implementation of .vtu format.
Still a lot of things to improve but right now fpakc can read a vtu mesh
and write the output in vtu.
Still to test:
Multiple geometries.
Double mesh.
Moving forward making vtu an independent format.
Now fpakc can generate nodes and edges from vtu input.
Next step is cells.
Some minor corrections in gmsh2 format to unify statements.
The reading of meshes needs a good overhaul.
Testing all geometries with vtu is gonna be fun...
