QFontMetrics::width was deprecated. This patch replaces all usages
by QFontMetrics::horizontalAdvance.
It also replace three usages of QTextEdit::setTabStopWidth
by QTestEdit::setTabStopDistance.
Changed the background to a lighter color to get the cursor visible again. To achive a good contrast, the text color for the selected line is now black. This combination works for dark and light mode.
.. Makes it easier to identify code that has been snaffled in from
other repositories and check licensing
.. The httpserver is now no longer optional, since it is delivered
as contributed source.
