This reverts commit 638be90b.

Stairs

See merge request !98

Merge dev/thomas/gui_tests

See merge request !89

When loading tmx, use SpNPC class for `character` layer

See merge request !109

Local-struct

See merge request !84

Big refactoring of ABC / arcade level : part 1, loading tmx maps in ABC

See merge request !108

Actually, what was (and still is) in level_arcade is not really arcade
dependent, it is mainly because this is code _intended_ to communicate with
the arcade GUI, but actually it is just sending payloads in the output_queue.
So we can also use it in test mode, by connecting the testing library to the
output_queue so we can check the payloads if we want to.

# Conflicts:
#	lib/level/level_abc.py
#	resources/credits.txt

I change read_input return in -1 if command not recognize and free in events drown for events and event_arg engines. I add verification of water to kill player in move_entity but due to this i can't free all memory because this function don't have access to all data of the game

i add a display symbol in floor because it's better for the show_map function when player see the console

if player do something like n 70 then he don't pass on the good tiles for level.py so we don't display to him the box with continue and he don't have acces to the button

This reverts commit 4b5fe4d4.

Now we can free map and game with the verify exit function because we call them in all levels