v0.13

Make generic boot_level function to boot any level.

Make a boot player function.

Make a boot log function.

Make element boot_collectible function.

Fix speed feeling by reduce animation speed when upper that 0.3 frame per behaviour update.

Make dummy_level_0.

Make dummy_level_1.

Prepare technicals (end entity for now).

Make a flag sprite.

Fix moving flaw that allow to not die when constantly press jumping key when falling.

Add a set_mood function to change colors and music for each level.

Start to work on color palettes.