Unclutter graphics package scope.
Moved some import statements from "graphics" package to "viewer" module.
It also avoid systematic import of everything in graphics when we only need one submodule.
/* Beremiz' header file for use by extensions */
#include "iec_types.h"
#define LOG_LEVELS 4
#define LOG_CRITICAL 0
#define LOG_WARNING 1
#define LOG_INFO 2
#define LOG_DEBUG 3
extern unsigned long long common_ticktime__;
int LogMessage(uint8_t level, char* buf, uint32_t size);
long AtomicCompareExchange(long* atomicvar,long compared, long exchange);