Free Editor.slf

In order to use the map editor, user should buy Unfinished Business version of the game and take Editor.slf from it.

Think about redrawing all the graphics from Editor.slf and including it into the distribution of JA2-Stracciatella. Editor.slf from Unfinished Business will not be necessary this way.

It shouldn't be too much of the work since Editor.slf is quite small - only about 3.5 Mb. It contains 79 sti files.