Merge branch 'jc/strbuf-add-lines-avoid-sp-ht-sequence'

The commented output used to blindly add a SP before the payload line, resulting in "# \t<indented text>\n" when the payload began with a HT. Instead, produce "#\t<indented text>\n". * jc/strbuf-add-lines-avoid-sp-ht-sequence: strbuf_add_commented_lines(): avoid SP-HT sequence in commented lines