MEDIUM: ssl: add mapping from SNI to cert file using "crt-list"

MEDIUM: ssl: add mapping from SNI to cert file using "crt-list"

It designates a list of PEM file with an optional list of SNI filter
per certificate, with the following format for each line :

    <crtfile>[ <snifilter>]*

Wildcards are supported in the SNI filter. The certificates will be
presented to clients who provide a valid TLS Server Name Indication
field matching one of SNI filter. If no SNI filter is specified the
CN and alt subjects are used.