bug#23156: 24.5; Allow vc-git annotate command options to be altered easily

[Dave Rolsky <autarch@urth.org>]

It'd be nice to be able to easily alter the options passed to "git
annotate".

The default value of "-C -C" makes this incredibly slow in large code
bases with many files.



In GNU Emacs 24.5.1 (x86_64-unknown-linux-gnu, GTK+ Version 3.10.8)
 of 2015-11-08 on houseabsolute.urth.org
Windowing system distributor `The X.Org Foundation', version 11.0.11501000
System Description:	Ubuntu 14.04.4 LTS

Important settings:
  value of $LC_MONETARY: en_US.UTF-8
  value of $LC_NUMERIC: en_US.UTF-8
  value of $LC_TIME: en_US.UTF-8
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

Major mode: Emacs-Lisp

Minor modes in effect:
  diff-auto-refine-mode: t
  show-paren-mode: t
  shell-dirtrack-mode: t
  auto-image-file-mode: t
  tooltip-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
Quit
Buffer "*Annotate QueueTester.pm (rev dave/rename-service-to-service_interface)*" has a running process; kill it? (y or n) n
Quit
Mark set
Quit
Buffer "*Annotate QueueTester.pm (rev dave/rename-service-to-service_interface)*" has a running process; kill it? (y or n) y
Making completion list... [3 times]
Mark saved where search started [3 times]
uncompressing vc-git.el.gz...done
Mark saved where search started

Load-path shadows:
/home/autarch/.emacs.d/elpa/helm-20160315.246/helm-multi-match hides /home/autarch/.emacs.d/elpa/helm-core-20160315.246/helm-multi-match
/home/autarch/.emacs.d/elpa/cperl-mode-20140309.122/cperl-mode hides /usr/local/share/emacs/24.5/lisp/progmodes/cperl-mode

Features:
(shadow sort mail-extr emacsbug message rfc822 mml mml-sec mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
sendmail rfc2047 rfc2045 ietf-drums mail-utils jka-compr dired-aux
vc-annotate mule-util log-view pcvs-util sgml-mode dired diff-mode vc
vc-dispatcher imenu go-mode url url-proxy url-privacy url-expand
url-methods url-history url-cookie url-domsuf url-util mailcap find-file
ffap url-parse url-vars markdown-mode derived thingatpt noutline outline
easy-mmode misearch multi-isearch help-mode cperl-mode perl6-detect
exec-path-from-shell edmacro kmacro vc-svn vc-git vc-hg paren tramp
tramp-compat auth-source eieio byte-opt bytecomp byte-compile cl-extra
cconv eieio-core gnus-util mm-util mail-prsvr password-cache
tramp-loaddefs cl-macs trampver shell pcomplete format-spec php-mode
advice help-fns cl gv cl-loaddefs cl-lib speedbar sb-image ezimage
dframe etags flymake compile comint ansi-color ring add-log cc-mode
cc-fonts cc-guess cc-menus cc-cmds cc-styles cc-align cc-engine cc-vars
cc-defs server image-file anchored-transpose-autoloads
android-mode-autoloads cperl-mode-autoloads fold-dwim-autoloads
go-mode-autoloads info easymenu less-css-mode-autoloads
nginx-mode-autoloads rx plsql-autoloads puppetfile-mode-autoloads
tidy-autoloads package epg-config time-date tooltip electric uniquify
ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd tool-bar dnd
fontset image regexp-opt fringe tabulated-list newcomment lisp-mode
prog-mode register page menu-bar rfn-eshadow timer select scroll-bar
mouse jit-lock font-lock syntax facemenu font-core frame cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev
minibuffer nadvice loaddefs button faces cus-face macroexp files
text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
dbusbind gfilenotify dynamic-setting system-font-setting
font-render-setting move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 279430 23393)
 (symbols 48 32783 0)
 (miscs 40 162 1272)
 (strings 32 63173 10855)
 (string-bytes 1 1936337)
 (vectors 16 29537)
 (vector-slots 8 974293 69159)
 (floats 8 105 439)
 (intervals 56 7618 0)
 (buffers 960 32)
 (heap 1024 65373 3292))