Support 4096-bit key generation on OpenPGP smartcards
Currently (GnuPG 1.x) the maximum size of keys that can be generated on a OpenPGP card is 3072 bits. Support for 4096 bit keys was added in GnuPG 2.0.18 and is not present in GnuPG 1.x.
Wheezy has GnuPG 2.0.19, so we should investigate installing both (see subticket).
Feature Branch: feature/6241-gnupg2
Blocked by #6015 (closed)