(still a stylistic warning)

Check first if astyle is present. In this way, when astyle is not compiled,
we get a single error instead of one error per file.

Updated headers for VES

Thanks @hanatok!

Also this after a discussion with @marcodelapierre

thanks to @marcodelapierre

This reverts commit 2128bada.

Giving false positive in master branch - no idea why and cannot debug it

This reverts commit 5ba9eb93.

- when using NAMD-like interface, also update the unique list of atoms.
- moved g2l out of dd, since it is also needed when not using MPI
  (in NAMD-like interface)

Partly implemented by @hanatok, see #359

More efficient on travis-ci