core (menu): allow to specify size in SideMenu: size menu now use 4 variable to open and close state: - size_hint_close - size_hint_open - size_open - size_close if one value of size_hint_open or size_hint_close tuples is None, the corresponding size is used instead.

[DEFAULT]
bridge = pb
log_level = debug
log_fmt = #[%%(levelname)s][%%(name)s] %%(message)s

[cagou]
log_level = debug
log_fmt = [%%(levelname)s][%%(name)s] %%(message)s