Introduce new global options: --ku-critical and --bc-critical

[TinCanTech]

These option allow X509 'critical' attributes to be used.

--ku-critical (--ku-crit): Configure 'keyUsage' to set 'critical' attribute.

--bc-critical (--bc-crit): Configure 'basicContraints' to set 'critical' attribute.

Use of these options is left to the discretion of the the user task.

Supported certificate types does not include 'email', 'codeSigning' or 'kdc'.