Non periodic BCs: Correct particle treatment
Implements #342 (closed):
- In the drift task, when not using periodic BCs, particles that are drifted outside of the box are inhibited and flagged for proper removal using the newly implemented mechanism.
- Add a few more checks in the rebuild to verify that this worked.
- Undo the check for non-zero masses when constructing multipoles.
- Small cosmetic changes related to the periodic flag.