[isabelle-dev] Isabelle/jEdit output panel

[Makarius]

Here is an interesting update in Isabelle/cbcccf2a0f6f: at first sight 
there should be hardly any difference in the Output panel appearance and 
behaviour, but it is now based on completely different technology.

The former Lobo/Cobra HTML4/CSS2 browser is no longer used, neither the 
new HTML5_Panel from JavaFX (which introduces its own complications). 
Instead, the existing semantic text rendering over regular jEdit text 
areas is applied to output as well.  This is in the best tradition of 
Emacs, where "everything is a buffer".  In Isabelle/jEdit almost 
everything is derived from TextArea, or better Rich_Text_Area.

This also means that tooltips, hyperlinks etc. should now work the same 
for Output, just as for the input text.

The next step will be to make tooltips and popups themselves use the same 
technology recursively.


If something breaks down unexpectedly, because I've overlooking something 
important, the old HTML4 panel is still available as Output1 for the 
moment.


 	Makarius