…twidth to 8 to match tabstop and softtabstop.
Some filetypes source other filetypes in their ftplugin. If that filetype called write#restart then futher filetypes would not get their say. If the first one wanted full mode and the later one wanted partial mode (e.g. text is sourced and then markdown is sourced) then the filetype would be stuck in full mode. write#restart() now only exists if b:writing *and* b:write_ft == &ft.
Made docs & functions conform to vim styles.