- Change: In ToolEngine, adds a static method "destroyAll()" that must be
called *before* the Hurricane database destruction. This is to avoid
a mis-oredering in destruction.
ToolEngines are stored in a property, property are part of the DBo
base object so are destroyed *after* the Cell derived object has been.
Thus ToolEngine are deleted *after* the Cell components and if they
still refers to it, we are doomed.
- Change: In display.xml, color support for displaying references.