use default gpg key for now

This is more useful as prompting the user for a key without
providing any alternatives.  Letting the user choose a key
with completion is possible and we should eventually do it.
support signing tags
remove magit-annotated-tag

Instead add `--annotate' opttion to `magit-key-mode-popup-tagging'.
Merge branch 'tag'
Adding some debug declare for debuging with edebug
magit-key-mode-popup-logging: add --grep= option

Setting this should also unset `--graph'.  Doing so requires
some big changes to the key-mode, so this will have to wait.
Docstring for magit-set-section-info
Merge branch 'grep'

Implements #739.
magit-merge: use git-merge options when calling git-commit
Merge remote branch origin/master'
Escape curly braces on Windows
Merge branch 'curly-windows'
magit.el: add "Setters" subsection to "Options"
allow setting diff options using a popup
Merge branch 'diff-options'
magit-with-git-editor-setup: surpress popping of process buffer

Set `magit-process-popup-time' to -1 so that the process buffer
does not popup while editing commit messages.  Fixes #768.
magit-tag: fix bugs

* Use prefix argument as advertised.
* Ensure message buffer pops up when creating an annotated tag.
handle amending the same in magit-{commit & tag}
magit-with-git-editor-setup: improve macro hygiene
use emacsclient from same directory as emacs process