Allow replacing each of the many sets of separate foo-{fg,bg,attr}

options with a single foo-style option. For example:

    set -g status-fg yellow
    set -g status-bg red
    set -g status-attr blink

Becomes:

    set -g status-style fg=yellow,bg=red,blink

The -a flag to set can be used to add to rather than replace a style. So:

    set -g status-bg red

Becomes:

    set -ag status-style bg=red

Currently this is fully backwards compatible (all *-{fg,bg,attr} options
remain) but the plan is to deprecate them over time.

From Tiago Cunha.

Makefile

@@ -113,6 +113,7 @@ SRCS=	arguments.c \
 	session.c \
 	signal.c \
 	status.c \
+	style.c \
 	tmux.c \
 	tty-acs.c \
 	tty-keys.c \

cmd-set-option.c

@@ -60,6 +60,9 @@ struct options_entry *cmd_set_option_flag(struct cmd *, struct cmd_q *,
 struct options_entry *cmd_set_option_choice(struct cmd *, struct cmd_q *,
 	    const struct options_table_entry *, struct options *,
 	    const char *);
+struct options_entry *cmd_set_option_style(struct cmd *, struct cmd_q *,
+	    const struct options_table_entry *, struct options *,
+	    const char *);
 
 const struct cmd_entry cmd_set_option_entry = {
 	"set-option", "set",
@@ -304,16 +307,21 @@ cmd_set_option_set(struct cmd *self, struct cmd_q *cmdq,
 		break;
 	case OPTIONS_TABLE_COLOUR:
 		o = cmd_set_option_colour(self, cmdq, oe, oo, value);
+		style_update_new(oo, o->name, oe->style);
 		break;
 	case OPTIONS_TABLE_ATTRIBUTES:
 		o = cmd_set_option_attributes(self, cmdq, oe, oo, value);
+		style_update_new(oo, o->name, oe->style);
 		break;
 	case OPTIONS_TABLE_FLAG:
 		o = cmd_set_option_flag(self, cmdq, oe, oo, value);
 		break;
 	case OPTIONS_TABLE_CHOICE:
 		o = cmd_set_option_choice(self, cmdq, oe, oo, value);
 		break;
+	case OPTIONS_TABLE_STYLE:
+		o = cmd_set_option_style(self, cmdq, oe, oo, value);
+		break;
 	}
 	if (o == NULL)
 		return (-1);
@@ -462,3 +470,23 @@ cmd_set_option_choice(unused struct cmd *self, struct cmd_q *cmdq,
 
 	return (options_set_number(oo, oe->name, choice));
 }
+
+/* Set a style option. */
+struct options_entry *
+cmd_set_option_style(struct cmd *self, struct cmd_q *cmdq,
+    const struct options_table_entry *oe, struct options *oo,
+    const char *value)
+{
+	struct args		*args = self->args;
+	struct options_entry	*o;
+	int			 append;
+
+	append = args_has(args, 'a');
+	if ((o = options_set_style(oo, oe->name, value, append)) == NULL) {
+		cmdq_error(cmdq, "bad style: %s", value);
+		return (NULL);
+	}
+
+	style_update_old(oo, oe->name, &o->style);
+	return (o);
+}

grid.c

@@ -37,7 +37,6 @@
 
 /* Default grid cell data. */
 const struct grid_cell grid_default_cell = { 0, 0, 8, 8, (1 << 4) | 1, " " };
-const struct grid_cell grid_marker_cell = { 0, 0, 8, 8, (1 << 4) | 1, "_" };
 
 #define grid_put_cell(gd, px, py, gc) do {			\
 	memcpy(&gd->linedata[py].celldata[px], 			\