Check ipAddrBlock and autonomousSysNum for criticality

Check ipAddrBlock and autonomousSysNum for criticality

These extensions MUST be marked critical. Criticality is determined by the
ASN1_BOOLEAN that is extracted and ignored after the FIXME a few lines
below each of the two hunks. Rather than getting the info from there, it's
easier to use an API call that checks what was already parsed by d2i_X509().

ok claudio job