move more logic up to the signable module
respond with metadata object so the returner can choose signed or raw
fix entity id
don't need reference ID method here any more
get raw algorithm auto from config
dont need this patching for figuring out issues any more
default to saml-idp config
fix top XML root
need to canonicalize XML before digesting
don't use memoized builder, more safe this way
redundant to have raw -> build