Added text-bubble slider. This is an extension of QSlider which
displays the slider value in the handle.
Added text-bubble slider by promoting existing QSliders in
input and ouput config ui files.
Removed two superfluous text fields. Unfortunately, Qt Creator
moved around a lot of XML lines during the save (file
optimization?) so this commit looks more extensive than it is.
Merge pull request #730 from kubark42/add-text-bubble-sliders-v2

Add text bubble sliders