The indicator is based on XCB-XKB and `libxkbcommon`. It can be tested
using the following configuration:
```
bar-list = ["bar"];
bar: {
position: "top";
block-list: ["ya_xkb"];
ya_xkb: {
exec: "YABAR_KEYBOARD_LAYOUT";
interval: 1;
};
}
```
The followinng new dependencies have been introduced:
- libxkbcommon-dev
- libxkbcommon-x11-dev
- libxcb-xkb-dev
Both work with libxcb and allow the usage of XKB through an XCB session.
In this case the session `ya.c` created by `src/ya_exec.c` can be used
for this indicator, so no extra X11 logic is needed.
As Ubuntu doesn't provide `playerctl` by default, it's better to make
this optional.
Furthermore another build with playerctl support has been added to the
CI matrix.
* redraw on exposure
* add override redirect and remove whitespace
* init all strut values to 0
* fix bspwm window order
* add icccm to travis
* add bspwm flag