Tweaks to support zero or more subkeys
Finished tweaks for zero or more subkeys
Added support for exporting I2P DataStructures as OpenPGP user attributes
Moved OpenPGPFile etc. into a separate folder
Bugfix: clear previous subkeys before an export
Split out Destination-specific code, so OpenPGPFile can be used for other I2P keys
Bugfix: clear OpenPGP fields before reading