Implement Tray Icons

This commit implements the StatusNotifierItem protocol, and enables
swaybar to show tray icons. It also uses `xembedsniproxy` in order to
communicate with xembed applications.
The tray is completely optional, and can be disabled on compile time
with the `enable-tray` option. Or on runtime with the bar config option
`tray_output none`.

Overview of changes:
In swaybar very little is changed outside the tray subfolder except
that all events are now polled in `event_loop.c`, this creates no
functional difference.

Six bar configuration options were added, these are detailed in
sway-bar(5)

The tray subfolder is where all protocol implementation takes place and
is organised as follows:

tray/sni_watcher.c:
	This file contains the StatusNotifierWatcher. It keeps track of
	items and hosts and reports when they come or go.
tray/tray.c
	This file contains the StatusNotifierHost. It keeps track of
	sway's version of the items and represents the tray itself.
tray/sni.c
	This file contains the StatusNotifierItem struct and all
	communication with individual items.
tray/icon.c
	This file implements the icon theme protocol. It allows for
	finding icons by name, rather than by pixmap.
tray/dbus.c
	This file allows for asynchronous DBus communication.

See #986 #343

1 files changed, 4 insertions, 0 deletions

diff --git a/include/sway/commands.h b/include/sway/commands.h
index 078652e7..f67df10f 100644
--- a/include/sway/commands.h
+++ b/include/sway/commands.h
@@ -157,17 +157,21 @@ sway_cmd cmd_workspace;
 sway_cmd cmd_ws_auto_back_and_forth;
 sway_cmd cmd_workspace_layout;
 
+sway_cmd bar_cmd_activate_button;
 sway_cmd bar_cmd_binding_mode_indicator;
 sway_cmd bar_cmd_bindsym;
 sway_cmd bar_cmd_colors;
+sway_cmd bar_cmd_context_button;
 sway_cmd bar_cmd_font;
 sway_cmd bar_cmd_mode;
 sway_cmd bar_cmd_modifier;
 sway_cmd bar_cmd_output;
 sway_cmd bar_cmd_height;
 sway_cmd bar_cmd_hidden_state;
+sway_cmd bar_cmd_icon_theme;
 sway_cmd bar_cmd_id;
 sway_cmd bar_cmd_position;
+sway_cmd bar_cmd_secondary_button;
 sway_cmd bar_cmd_separator_symbol;
 sway_cmd bar_cmd_status_command;
 sway_cmd bar_cmd_pango_markup;