TODO:
* Fit improvements: T5994
* Extend FileInfoDialog to show information about HDF5, NetCDF, FITS-files, etc.: T5063
* Data set operations: T8642
* Scientific notation in double spin boxes: T2001
* auto-/cross correlation and convolution/deconvolution (Analyis)
* use KSharedConfig instead of KConfig?
* switch to the new signal-slot syntax in Qt
* restoring of dialog sizes doesn't work. KWindowConfig::saveWindowSize(windowHandle(), conf) and KWindowConfig::restoreWindowSize(windowHandle(), conf) don't seem to do the correct job. Also, https://bugs.kde.org/show_bug.cgi?id=386884.
* switch to the scientific format for axis labels for small numbers similar to what is already done for big numbers (Alexander)
* "default scheme" in the menu for color schemes (Alexander)
* the logic in AxisPrivate::retransformTickLabelStrings() reduces the precision too much in some cases like for the x-region [0,6] with 6 major ticks where we show ticks at 0, 1, 2, 4, 5 and 6 instead of placing the ticks at 0, 1.2, 2.4, 3.6, 4.8 and 6.0.