Merge branch 'jk/color-variable-fixes'

Some places in the code confused a variable that is *not* a boolean
to enable color but is an enum that records what the user requested
to do about color.  A couple of bugs of this sort have been fixed,
while the code has been cleaned up to prevent similar bugs in the
future.

* jk/color-variable-fixes:
  config: store want_color() result in a separate bool
  add-interactive: retain colorbool values longer
  color: return bool from want_color()
  color: use git_colorbool enum type to store colorbools
  pretty: use format_commit_context.auto_color as colorbool
  diff: stop passing ecbdata->use_color as boolean
  diff: pass o->use_color directly to fill_metainfo()
  diff: don't use diff_options.use_color as a strict bool
  diff: simplify color_moved check when flushing
  grep: don't treat grep_opt.color as a strict bool
  color: return enum from git_config_colorbool()
  color: use GIT_COLOR_* instead of numeric constants

builtin/add.c

@@ -200,7 +200,7 @@ static int edit_patch(struct repository *repo,
 
 	argc = setup_revisions(argc, argv, &rev, NULL);
 	rev.diffopt.output_format = DIFF_FORMAT_PATCH;
-	rev.diffopt.use_color = 0;
+	rev.diffopt.use_color = GIT_COLOR_NEVER;
 	rev.diffopt.flags.ignore_dirty_submodules = 1;
 	out = xopen(file, O_CREAT | O_WRONLY | O_TRUNC, 0666);
 	rev.diffopt.file = xfdopen(out, "w");