vere: support saving scry jam to directory
vere: support saving scry jam to directory

And default to the scry path, instead of just "scry.jam".

urbit/urbit,urbit/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,urbit/urbit,urbit/urbit,ngzax/urbit,urbit/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit,ngzax/urbit