Fluid: restructuring and rejuvenation of the source code.

* Add classes for application and project
* Removed all globals from Fluid.h
* Extracting args and project history into their own classes
* Moving globals into Application class
* Initialize values inside headers for some classes.
* Undo functionality wrapped in a class inside Project.
* File reader and writer are now linked to a project.
* Avoid global project access
* Nodes (former Types) will be managed by a new Tree class.
* Removed static members (hidden globals) form Node/Fl_Type.
* Adding Tree iterator.
* Use nullptr instead of 0, NULL, or 0L
* Renamed Fl_..._Type to ..._Node, FL_OVERRIDE -> override
* Renaming ..._type to ...::prototype
* Splitting Widget Panel into multiple files.
* Moved callback code into widget panel file.
* Cleaning up Fluid_Image -> Image_asset
* Moving Fd_Snap_Action into new namespace fld::app::Snap_Action etc.
* Moved mergeback into proj folder.
* `enum ID` is now `enum class Type`.

1 files changed, 4 insertions, 3 deletions

diff --git a/fluid/widgets/Code_Editor.cxx b/fluid/widgets/Code_Editor.cxx
index a145b5055..b4379c845 100644
--- a/fluid/widgets/Code_Editor.cxx
+++ b/fluid/widgets/Code_Editor.cxx
@@ -1,6 +1,5 @@
 //
 // Code editor widget for the Fast Light Tool Kit (FLTK).
-// Syntax highlighting rewritten by erco@seriss.com 09/15/20.
 //
 // Copyright 1998-2025 by Bill Spitzak and others.
 //
@@ -15,6 +14,8 @@
 //     https://www.fltk.org/bugs.php
 //
 
+// Syntax highlighting rewritten by erco@seriss.com 09/15/20.
+
 //
 // Include necessary headers...
 //
@@ -230,11 +231,11 @@ Code_Editor::Code_Editor(int X, int Y, int W, int H, const char *L) :
  */
 Code_Editor::~Code_Editor() {
   Fl_Text_Buffer *buf = mStyleBuffer;
-  mStyleBuffer = 0;
+  mStyleBuffer = nullptr;
   delete buf;
 
   buf = mBuffer;
-  buffer(0);
+  buffer(nullptr);
   delete buf;
 }