code and adds support to ASN1_TYPE and asn1parse.

support for subject and issuer alt name. Add a new ASN1 macro and fix a
nasty bug that left an ASN1 buffer modified on an error condition with
IMPLICIT tagging.

the main library, but only with printing at present. To see this try:
openssl x509 -in cert.pem -text
on a certificate with some extensions in it.

This is the result of a "make errors" with the new error building functionality
in place.