Add verify functionality, including the ability to get the validated
chain. This means that it is now possible to get information about the
root-certificates that were used to secure a connection.

Intermediate commit before changing the script interface again.

addresses BIT-953, BIT-760
X509 file analyzer nearly done. Verification and most other policy scripts
work fine now.

Todo:
 * update all baselines
 * fix the circular reference to the fa_file structure I introduced :)
   Sadly this does not seem to be entirely straightforward.

addresses BIT-953, BIT-760