libee/triangle.c:
+ Wrote ee_draw_triangle() and ee_draw_thin_triangle().
libee/box.c:
+ Wrote ee_draw_box(), ee_draw_thin_box() and ee_fill_box().
libee/conic.c:
+ Wrote ee_fill_ellipse().
+ First attempt at ee_draw_thin_ellipse(), to be reworked.
test/demo.c:
+ Merged demo_lines() and demo_thin_lines().
+ Merged demo_triangles() and demo_outlined_triangles().
+ Wrote demo_box().
+ Use ee_fill_ellipse() in demo_all().
