Trylle

implement add/1, skip/2 functions

implement --library-path option as the alias of -L option

fix reduce syntax to emit results for each initial value

fix last/1 to yield no values when the argument yields no values

fix limit/2 to emit an error on negative count

fix @uri and @urid formats not to convert space between plus sign

fix resolving search paths of import statements in the query

improve time functions to accept fewer element arrays