Editor mode

[hallucino]

Many things need to be improve:

• [x] Display the map section
• [x] zoom in/out for map edition
• [x] save map modification
• [x] Copy/Paste a sprite
• [x] zoom in/out for sprite edition
• [x] edit sprite's flags
• [x] save sprite modification

[hallucino]

I think we are good for this version at least. We have basic support for sprite/map with zoom, move, copy/paste, erase