Impliment i3-style marks

This commit adds three commands to sway: `show_marks`, `mark` and
`unmark`. Marks are displayed right-aligned in the window border as i3
does. Marks may be found using criteria.

Fixes #1007

1 files changed, 1 insertions, 0 deletions

diff --git a/sway/config.c b/sway/config.c
index 46faf643..c8432a2a 100644
--- a/sway/config.c
+++ b/sway/config.c
@@ -329,6 +329,7 @@ static void config_defaults(struct sway_config *config) {
         config->auto_back_and_forth = false;
         config->seamless_mouse = true;
         config->reading = false;
+        config->show_marks = true;
 
         config->edge_gaps = true;
         config->smart_gaps = false;