Removing netdb.i2p2.* certs

These have not been used for some time. netdb.i2p2.no is using an *.i2p2.de
cert from Commodo.
rename i2pproject cert

The other self-signed certs are named after the host that they're being used
for. Maintaining this naming scheme will make automated testing easier.
remove certs that are no longer used
Add script to check reseeder host certificate validity