Implemented a general way to use of prompt widget.
Implemented a general way to use of prompt widget.

Closes #1104

kynikos/qtile,cortesi/qtile,qtile/qtile,soulchainer/qtile,ramnes/qtile,zordsdavini/qtile,kynikos/qtile,flacjacket/qtile,flacjacket/qtile,qtile/qtile,tych0/qtile,ramnes/qtile,frostidaho/qtile,frostidaho/qtile,cortesi/qtile,soulchainer/qtile,tych0/qtile,zordsdavini/qtile