Tying validation errors to certificates

Tying validation errors to certificates

When Squid sends errors to the certificate validation daemon, the daemon cannot
tell which certificate caused which error. This is especially bad because the
validator has to return that same information in the response (the response
format requires the validator to match the error to the certificate).
This patch adjust the validation request format to provide that information
using a set of the following key=value pairs:

    error_name_N=the name of the certificate error number N
    error_cert_N=the ID of the certificate which caused error_name_N

where N is non-negative integer. N values start from zero and increase
sequentially.

This is a Measurement Factory project