Add public accessible PublicKeyData/PublicKeyScanner classes
Reduce amount of gpg calls when importing/exporting keys.
Fix rpmdb key import/export (bnc#828672)
No rpmdb key import in readony mode (bnc#828672)
Provide additional keys data in case the ASCII armored blob containes multiple keys
fix key expiry date parsing (bnc#828672)

old gpg versions do not have --fixed-list-mode as default.
Merge branch 'bnc#828672'
remove deprecated methods
changes 13.5.0 (5)