Merge 'kn/for-each-tag-branch' into kn/for-each-tag

* kn/for-each-tag-branch: for-each-ref: add '--contains' option ref-filter: implement '--contains' option parse-options.h: add macros for '--contains' option parse-option: rename parse_opt_with_commit() for-each-ref: add '--merged' and '--no-merged' options ref-filter: implement '--merged' and '--no-merged' options ref-filter: add parse_opt_merge_filter() for-each-ref: add '--points-at' option ref-filter: implement '--points-at' option tag: libify parse_opt_points_at() t6302: for-each-ref tests for ref-filter APIs