Add support for the use of x509-types as template for the distinguished names.

Add support for the use of x509-types as template for the distinguished names.

Added the option type for gen-req. You can define section for distinguished_name,
and script will use field names and values from it when create request.
You can use interactive or non-interactive format of Distinguished name section.
Two examples added:
  * prompt_example - interactive
  * silent_example - non interactive