Revised QxtProgressLabel docs.
Revised QxtProgressLabel docs.

mmitkevich/libqxt,hrobeers/qxtweb-qt5,hrobeers/qxtweb-qt5,mmitkevich/libqxt,mmitkevich/libqxt,hrobeers/qxtweb-qt5,hrobeers/qxtweb-qt5,hrobeers/qxtweb-qt5,mmitkevich/libqxt