Now there is a link to the online documentation

The runoff should now be more or less supported

Some missing keys in the katabatic flows module have been added, some
unnecessary keys removed from MeteoIO (no need for POIs there). Some
file extensions are now specified as filters when it makes sense.

A few errors have also been fixed for Snowpack (missing the SNOW_WRITE
key and wrong type for HOAR_DENSITY_BURIED)

The WSL_HACK of the ARGOS plugin is defined in the metafile, not in the
ini file!

The configuration for MeteoIO's Argos plugin has been added

The spatial_resampling, 1d interpolaitons and 2d interpolations have
been renamed to have more consistent naming.

This is necesary for the packaging (it is much beter to have an
"inishell-apps" folder in /usr/share than an "applications" folder)

And fixed an inconsistent option (between SUPPR on single parameters and
on time).

When both a default value and precision=... where provided in the xml
file, the precision was reset to the default precision. Now the default
precision is reset to the XML provided precision.

In order to give the user the required flexibility to enter the numeric
values he/she wants to, precision specifications have been almost
everywhere in the xml files (a few places still rely on the default
settings because it makes sense). The units have also been added where
possible.

This addresses issue 834: files that will be read from a METEOPATH
should be stripped of their path otherwise the path appears twice. On
the other hand, this means that since there is no link to the METEOPATH
(or similar variable), we don't know which directory the files belong
to, so we can not validate anything (beside non-empty file name). This
is better than generating a wrong configuration file but still not
perfect...

When doing a merge, keep, exclude, etc that rely on a station ID, since
the user might have little control over the station ID we need to be
able to support some flexible naming (including containing '-').

Since this might generate large logs, this could be necessary...

The virtual stations are given as "VSTATIONx", not "POSITIONx"!
Moreover, more links to the online documentation have been added and the
syntax highlighting (in the PreviewWindow) now supports the coordinates
specifications (otherwise, coordinates provided with ";" were shown as
comments).

better "unsaved changes" warning.

It should finally be relatively clear to the user what happens when an
INI is opened, and closed seemingly without changing anything - namely
that the application may have inserted mandatory keys.

For the Kalman filter this is not possible yet because of changes
requiring anything entered in a Number's expression to be a complete
formula.

Moreover, the license for the lines numbering has been clarified and is
now advertised in the About window

The goal being to avoid writing out lots of keys that already have
defaults in their respective applications

Now MeteoIO provides a first application: meteoio_timeseries and it is
handled by the meteoio workflow (instead of the hacky data_converter).

Small touch up on the Numbers: default decimal precision is now 2 (for a
precision up to the percent)

Modernize signal mapping in PreviewEdit (better compile time checks), re-add line number safety margin (sorry, my oversight).

(old style cast, and "no out-of-line virtual method definitions")

Use recommended call for text width. I looked this up a while ago for the Alternative width calculation. This way we stay happy with the default Qt 5.9 and don't require 5.11 just for this call.

(Ok I admit - I don't want to update Qt myself. But luckily it is the correct call.)

The fonts are now setup in the constructor. An unnecessary script has
been deleted.