Remove IPSec example certs and generation script

IPSec has been purged from this branch (that's in the `animal_control`
branch) because it's not ready for real-world usage. It probably never
will be usable, simply as there is not good API for controlling and
configuring it (not to mention cross-platform issues).
Merge pull request #2 from ipop-project/remove-certs

Remove IPSec example certs and generation script