Merge branch 'md/list-objects-filter-combo'

The list-objects-filter API (used to create a sparse/lazy clone) learned to take a combined filter specification. * md/list-objects-filter-combo: list-objects-filter-options: make parser void list-objects-filter-options: clean up use of ALLOC_GROW list-objects-filter-options: allow mult. --filter strbuf: give URL-encoding API a char predicate fn list-objects-filter-options: make filter_spec a string_list list-objects-filter-options: move error check up list-objects-filter: implement composite filters list-objects-filter-options: always supply *errbuf list-objects-filter: put omits set in filter struct list-objects-filter: encapsulate filter components