V3.5.1-0

New functionality and updates in general physics algorithms:

• #381:
  • enable backward search for iterations seeded by pixel triplets and pixel doublets (in response to https://its.cern.ch/jira/browse/PDMVRELVALS-136);
  • update hit selection windows, including backward search.
• #382: tighten candidate filter for pixelLessStep, after #381.

Additional notes:

• #381 corresponds to update of mkFit JSON configuration files.