firmware: control logic moved to a separate module
- buttons.c now controls status LEDs only when setting parameters
- pattern.c:
can use NULL instead of off_pattern
has number_pattern() than can also set up inverted patterns
contains only number and boot patterns as static variables
can reload all patterns if some state changes
- ambient.c resets all patterns when ambient zone changes
- control.c:
- now contains almost all pattern strings, only those needed by
other modules are exported
- status LED and illumination LED can be controlled by buttons.c
- separate _pattern_select() function for each LED