reset loaded messages counts on new PLC program trasnfer
This fixes the problem that first message from newer PLC program maybe
lost, if it's issued before first PLC log fetching.
Closes #23
int CheckRetainBuffer(void){ return 1;}void ValidateRetainBuffer(void){}void InValidateRetainBuffer(void){}void Retain(unsigned int offset, unsigned int count, void *p){}void Remind(unsigned int offset, unsigned int count, void *p){}