Merge branch 'jc/gpg-lazy-init'

Instead of forcing each command to choose to honor GPG related
configuration variables, make the subsystem lazily initialize
itself.

* jc/gpg-lazy-init:
  drop pure pass-through config callbacks
  gpg-interface: lazily initialize and read the configuration

diff --cc builtin/am.c
Simple merge

diff --cc builtin/commit-tree.c
Simple merge

diff --cc builtin/commit.c
Simple merge

diff --cc builtin/log.c
Simple merge

diff --cc builtin/merge.c
Simple merge

diff --cc builtin/pull.c
Simple merge

diff --cc builtin/push.c
Simple merge

diff --cc builtin/receive-pack.c
Simple merge

diff --cc builtin/send-pack.c
Simple merge

diff --cc builtin/tag.c
Simple merge

diff --cc fmt-merge-msg.c
Simple merge

diff --cc gpg-interface.c
Simple merge

diff --cc sequencer.c
Simple merge