def extract_chapter(title)
		title =~ /^((\d+\.)*) (.+)$/
		chapter = $1
		pure_title = $3
		if !chapter.nil? && !chapter.empty? && pure_title && !pure_title.empty?
			return [chapter, pure_title]
		else
			return nil
		end
	end
def extract_chapter(title)
		title =~ /^((\d+\.)*) (.+)$/
		chapter = $1
		pure_title = $3
		if !chapter.nil? && !chapter.empty? && pure_title && !pure_title.empty?
			return [chapter, pure_title]
		else
			return nil
		end
	end
Given a title with a chapter number, e.g. "6.1 Installation using tarball",
 splits the two up.