Implement mechanism to translate custom syntax to tinyexpr before styling (so e. g. hardcoded substitutions are allowed exactly like in some filters)

Since we now do not "allow" free text anymore and request SLF expression syntax, a few other things will need to be considered (but in the end it'll be tied together more tightly).

The static function felt like bad design ever since the Textfield
started using it...

-Move setting to 'preview' XML section because it exists from another setting now
-Remove obsolete documentation
-Clear status on TerminalView clear ("Process terminated" etc.)
-Remove useless _ from regex (it is checked by \w)
-Extend INIParser unit test with *::EXCLUDE example key
-Cosmetics
(Might want to clear settings with ./inishell -ce)

(it is licensed under BSD instead of GPL)

Now the line numbering can be considered ready to go

This addresses issue 827

Since we will never use images, etc in this editor...

Stealing code from MeteoIO, the copyright notice now shows the user name
and domain name (if available)

This fixes issue 829 with MeteoIO's "*::EXCLUDE" kind of keys. Moreover,
the new option for MeteoIO's deGrass filter has been included in the xml
file.

Also fixed a wrongly defined boldface in the terminalview and an invalid
icon format in the .desktop file

Allow : and _ in INI key names for preview syntax highlighting (not perfect but better). Set tooltip for Number panel when an expression is used.

Noteworthy: Removed fixed shortcut in doc because it is OS-dependent.

(quick work - if ever used it could all be revised)

User settings are case-sensitive (tiny performance edge in INIParser), this was not matching the settings page. Clear a warning.

A small inconsistency has been fixed in Number.cc (now using the
background color instead of hard-coded white). The PATH is now expanded
to include the directory where inishell is (this will be convenient for
packaging with small applications). The NSIS templates for Windows have
been copied, but there is still work to do before it can be useful.

font size properly... so now they are built more cleanly and do that.

This mechanisms of keeping things left-aligned is a little tedious, but
it looks like this should be done throughout INIshell's panels at some
point... would get rid of the spacer and some (hypothetical) problems.

Erase 'close settings' menu. There is now a very visible tab close button and no other program has this. ESC still works.

Thanks to the bold items I see that the preview toolbar was not being disabled together with the menu. Thanks to the Preview editor I see that loading the settings would cause the application name to change.

Otherwise, the coordinates provided to the geoservice were wrong...

As well as a minot tweak in the project file

Of course, this means that "performant=true" must be replaced by
"pre-generate=false" for the same behavior.

Some new icons have been added

A few more icons have been added and a few colors tweaked for the dark
theme (sorry)

header' entry.

Some cleanup.

Unfortunately this seems to care about our syntax highlighting and I
can't find how to change the paragraph sign's color.

be given - this will flash the frame's border, enabling contextual help.