unexport the whole module and export only what make sense.
add haddock description
add haddock descrition and remove useless table.
export DnElement.
add haddock description.
reindent
add support for encoding CRL.
expose CRL types
remove unused import.
add CRL arbitrary test.
move to asn1-types 0.2
fix compilation of x509-validation
update to asn1-type 0.2