def hash_to_styles(hash, separator = '; ')
			unless hash.empty?
				return hash.map{|e| "#{e[0]}: #{e[1].join(' ')}"}.join(separator)
			else
				return nil
			end
		end
def hash_to_styles(hash, separator = '; ')
			unless hash.empty?
				return hash.map{|e| "#{e[0]}: #{e[1].join(' ')}"}.join(separator)
			else
				return nil
			end
		end
make a CSS style-let from a Hash of CSS settings