Implemented question 5 (modes append and vertex)

- A polygon now contains a v_last pointer on the last vertex
- v_last appears in functions append and remove vertex
- There are two modes in main.c
	* Append : default mode, drawing polygons
	* Vertex : we can select, delete or move each vertex in the current polygon
Erase Bad Whitespace

You bad bad whitespace.

Signed-off-by: Celelibi <celelibi@gmail.com>
Don't loop to find the last vertex of a polygon

Use the pointer to the last vertex, now we have it.

Signed-off-by: Celelibi <celelibi@gmail.com>
Maintain a counter of vertex in the polygons

This will eventually speedup the polygon filling.

Signed-off-by: Celelibi <celelibi@gmail.com>
Remove useless parameter for vertex count

Now the number of vertex of a polygon is globally known, there is no
need to recompute it nor to optimize to not-recompute it.

Signed-off-by: Celelibi <celelibi@gmail.com>
Don't allocate memory in polygon_ysorted_vertex

Now the number of vertex is globally known, this optimization is no
longer needed and the memory management can be done in a more usual way.

Signed-off-by: Celelibi <celelibi@gmail.com>
Clean the active_edge before filling it

Don't forget to clean the structure you're about to fill in order to get
rid of old garbage. And don't forget to refill the linked list field.

Signed-off-by: Celelibi <celelibi@gmail.com>
Partial resolution of filling bug on the edges

The starting error wasn't set properly.

Signed-off-by: Celelibi <celelibi@gmail.com>
Typo dans les commentaires

s/quadran/cadran/g

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