Toggle load by a short button press, enter menu with a long button press when in CC mode

Possible solution for issue #30
With :
Flash used: 30872 of 32768 bytes (94,2 %).
SRAM used: 3911 of 4096 bytes (95,5 %).

Without :
Flash used: 29696 of 32768 bytes (90,6 %).
SRAM used: 3407 of 4096 bytes (83,2 %).

Diff :
Flash : +1176 bytes
SRAM : +504 bytes