The tabs are now solarized and match the user guide (in some way). It is
now a normal list instead of within Inishell-frames.
(issue #879)

According to the structure that was sketched for the Text panel.
The TOC needs a rework...

It can display an image with a few simplistic options:
  - image path
  - image caption
  - alt text if unloadable
  - alignment
  - border
  - the usual help text

(issue #879)

Analogous to the currently loaded app name now the app path is also
available. Minor cleanup of an obsolete parameter.

When it's multi-line we have a label.
Not extremely pretty yet...

Also fixes a link in the dev help.

Wth bullet and numbered lists we are set here now.

The dev help for the Text panel has been prettified and rewritten with
new features.
This draft for a general structure should be used in all other panels
whenever there is time to do it (i. e. use all the same frames for a
uniform look).

Only internal:
- switch to <section>...</section> notation instead of specifiying it
  for each panels (seems more logical in text-heavy XMLs)
- TOC links now parametergroup and also at bottom

For one-liners if the text is too long we add the height of the scroll
bar that now appears to the line height.

A warning was always shown, but now that potentially users will also
link topics we avoid adding unused tabs.

Now the PreviewEdit is properly parented and the garbage collector can
cascade down to the syntax highlighters (which are parented through
their text document).

- INI syntax highlighting moved from PreviewWindow to PreviewEdit
- Split up BSD code with separate header because most of it is actually
our own by now...

If there is syntax highlighting going on, we have higher (bold) lines.

So far, this panel would not accept empty keys with an overridden label
(because it is one of the panels that can be very compact).

... if enabled in the attributes.

A Copytext like a Helptext is meant to display some text, but this time
in a normal text box that can be copy/pasted easily.
This is developed to offer XML snippets, but since it comes from Atomic
everything is ready should it ever be desired to contribute to INI
files.

Now if no element key is given the frame is selected but nothing
highlighted.

Now in addition to doc:// we can link to dev://

People who have never seen GitLab may not stumble across the wiki on a
quick look.

... because it is now so prominently displayed and the first thing a
user see on the project page.

A wiki has been started for this.
Links to mio, sp, a3d, niviz are left in place at this point.

Some users will want to know where a link leads before following it, so
now this is temporarily displayed in the status bar.

The users will want to know where a link leads, now this is
displayed in the status bar temporarily.