This allows the "label" callback to adjust the textbox itself.
`tasklist_label` is changed to make use of it and supports new style
arguments: `font_focus`, `font_urgent` and `font_minimized`.
Closes https://github.com/awesomeWM/awesome/pull/313.
When windows are set as "above", they will basically behave as "ontop"
(under normal circumstances) and therefore an indicator is useful to get
displayed in that case, too.
Closes https://github.com/awesomeWM/awesome/pull/325.
Currently `tasklist_update` gets triggered often, because it listens to
a lot of signals.
This patch makes it only call the last one through `timer.delayed_call`.