core/packs/pack-ido-buffer.el: Add ido-vertical-mode

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
core/packs/pack-guide-key.el: More configuration

Move the popup window to the bottom, and enable
recursive-key-sequence-flag.

Signed-off-by: Gergely Nagy <algernon@balabit.hu>
core/packs/pack-git.el: Add gitconfig-mode and gitignore-mode

Signed-off-by: Gergely Nagy <algernon@balabit.hu>