Merge branch 'jk/ref-filter-lrstrip-optim'

Code clean-up. * jk/ref-filter-lrstrip-optim: ref-filter: clarify lstrip/rstrip component counting ref-filter: avoid strrchr() in rstrip_ref_components() ref-filter: simplify rstrip_ref_components() memory handling ref-filter: simplify lstrip_ref_components() memory handling ref-filter: factor out refname component counting