export pubkeyToAlg
implement signature verification
WIP add more checks
move Extension parsing into its own module and create new wrapper types

ExtensionRaw is now a proper type, instead of a tuple3.
add a FIXME for one of DNinner method that is propably incorrect.
fix test.
simplify header
remove WIP types and implement CRL parsing.
use getopt and split command better
factor out stuff
add a way to print CRL.
repair key parsing.
remove old key code.
various fixup
remove old stuffs
export the whole DN module.
WIP validation