[docmaker] Allow empty lines in `<Order>' blocks. Before this patch, the suggested order of entries stopped at the first empty line. Obviously, nobody noticed that this problem caused a much reduced set of links in the `Synopsis' sections; in particular, the `<Order>' blocks contain a lot of entries that wouldn't be listed otherwise... * src/tools/docmaker/content.py (DocBlock::get_markup_words_all): New function to iterate over all items. (DocSection::process): Use it.