Merge branch 'correct_position_checks_after_drift' into 'master'

Added debugging checks to verify that the particles are in the correct frame after the shift in DOPAIR1 and DOPAIR2. The check takes into account directions and drift since last rebuild.

Corrected the same check in the vectorized versions of the pair interactions. This was not using the correct criterion for the maximal displacement any particle can have had since the last rebuild.

See merge request !431