A missing icon (on Mac) has also been added

They are not used by Snowpack, except when doing spatial resampling (which is not implemented in the xml yet but will be soon)

Some obsolete calls for Mac have also been removed.

Merge dark mode and settings loading changes

Apply changes to settings and dark mode

Merge necessary changes in the settings loading

This is not only necessary for new features but also cleans up a
lot.

Mathias, I was not sure if you would like to try darkmode on Windows
unless disabled. The logic for it is in colors.cc::useDarkTheme()

This is not only necessary for an upcoming feature but also cleans up a
lot.

Implement a 'placeholder' property in Textfields and Selectors - if the text is empty this is displayed grayed out by Qt and can tell a user what to enter

Do mini TODO: start showing a hidden Number when the minus sign is entered. It's not perfect but better.

rid of obsolete info.

Alternative way of presenting the data creators (save space in crowded section, uniform with MeteoIO doc)

rid of obsolete info.

XML. Also enable 'textmode' for some raw editing elements.

Set longlabel="true" to align a list of options containing names wider
than the standard column width.

Thanks again Michael for your help and advices!

The active/inactive icons have been redone as svg. Formulas are now marked as invalid as long as they are...

I always expect something to happen on Strg+F in the preview... so the find function has been implemented.

Outource some code instead of tripling it. Closing the preview via key
board is a bit more intuitive (strg+w closes one tab after the other
until it finally closes the main window).

Moreover, one color used in meteoIO_filters has been tweaked to be more visible in dark theme

Now the QPalettes are not used, but all colors go through our getQColor() function. It detects if a light or dark theme is used and swapps a few colors accordingly

Fix two subtle bugs where a wrong error would be displayed and in some situations the help could not be loaded via keyboard shortcut

Implement XML command to automatically open an INI file after an application/simulation has been opened.

This method is easily ship-able (unlike the autoload checkbox, which is saved locally) and I reckon this could be an early obstacle for a new user - 'the example simulation is clicked but there are no INI settings visible??'

They were left over from testing out GUI elements and may have been the
oldest untouched INIshell code... now they are cleaner and less
intrusive.