Added new structures

- Struct polygon (list of points)
- Struct drawing (list of polygons)
- Goodbye my typedef, goodbye my friend, you have been the one, you have been the one for me
Fixed Bresenham

3eme octant : x++ -> x--
Polygon is now a chained list

Here comes the "next" pointer
Translated french to english and did several modifications

- sommet is now called vertex
- sommet_add and sommet_remove are now called polygon_append_vertex and polygon_remove_vertex
- sommet_get_last is now called polygon_get_last_vertex and became static
- created new functions (but no code inside yet)
Vertex is now a double chained list

- Modification of both functions append and remove
- main.c is up-to-date
Intentation fix

Removed tabs and space at the end of line.

Signed-off-by: Celelibi <celelibi@gmail.com>