Merge branch 'rs/strbuf-expand'

* rs/strbuf-expand: remove the unused files interpolate.c and interpolate.h daemon: deglobalize variable 'directory' daemon: inline fill_in_extra_table_entries() daemon: use strbuf_expand() instead of interpolate() merge-recursive: use strbuf_expand() instead of interpolate() add strbuf_expand_dict_cb(), a helper for simple cases