Rearrange slides and layer and flood fill fix

The order of layers and slides can now be edited in the tree view by using drag and drop. All the code for this is in the TOAD library itself which I do consider pretty cool. The behaviour is not perfect yet and needs some tuning in the future but: Here it is!

I have also fixed two issues with the flood fill tool and I am also quite happy with it.

So what's next?

• The flood fill tool still ignores
  • transformation matrices in TFPath,
  • more than two lines at an intersection (because of this it's not always possible to fill next to an already filled area) and
  • other figures than TFPath like TFRectangle, TFGroup, etc.
• Snap to line: without this one has to close all gaps manually before the flood fill tool can be used.
• Switching between the selection and direct selection tool should not clear the selection.
• Fischland should save the open windows and their screen location for the next session.
• Remove the buttons which open the colour editor and the colour palette from the toolbox and provide the following three buttons instead:
  • do not fill
  • fill with stroke colour
  • fill with fill colour
• Text editing must become easier and reuse the algorithms from TTextArea.
• New figures like rounded rectangles and speech bubbles.
• There are some issues when working with multiple views and it should also be possible to view different pages of the same document at the same time.

Now, that's quite a list. Guess I should set up something like Bugzilla again...