Merge branch 'mg/gpg-fingerprint'

New "--pretty=format:" placeholders %GF and %GP that show the GPG
key fingerprints have been invented.

* mg/gpg-fingerprint:
gpg-interface.c: obtain primary key fingerprint as well
gpg-interface.c: support getting key fingerprint via %GF format
gpg-interface.c: use flags to determine key/signer info presence

diff --cc gpg-interface.c
Simple merge

diff --cc pretty.c
Simple merge