SignPages: Made the signature extraction a bit more robust

By not extracting all values from the record.

From the documentation:

 5. Field:  KeyID
 6. Field:  Creation Date (in UTC).  For UID and UAT records, this is the
            self-signature date.  Note that the dae is usally printed
            in seconds since epoch, however, we are migrating to an ISO
            8601 format (e.g. "19660205T091500").  This is currently
            only relevant for X.509, A simple way to detect the format
            is be scannning for the 'T'.
 7. Field:  Key or user ID/user attribute expiration date or empty if none.
 8. Field:  Used for serial number in crt records (used to be the Local-ID).
            For UID and UAT records, this is a hash of the user ID contents
            used to represent that exact user ID.  For trust signatures,
            this is the trust depth seperated by the trust value by a
            space.
 9. Field:  Ownertrust (primary public keys only)
            This is a single letter, but be prepared that additional
            information may follow in some future versions.  For trust
            signatures with a regular expression, this is the regular
            expression value, quoted as in field 10.