Issuer Sign Tool extention support

Issuer Sign Tool extention support

Issuer Sign Tool (1.2.643.100.112) The name of the tool used to signs the subject (ASN1_SEQUENCE)
This extention is required to obtain the status of a qualified certificate at Russian Federation.
RFC-style description is available here: https://tools.ietf.org/html/draft-deremin-rfc4491-bis-04#section-5
Russian Federal Law 63 "Digital Sign" is available here:  http://www.consultant.ru/document/cons_doc_LAW_112701/

Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/11216)