Add log functions.

1. REPORT_INFO : wrapper for SC_REPORT_INFO
2. REPORT_WARNING : wrapper for SC_REPORT_WARNING
3. REPORT_ERROR : wrapper for SC_REPORT_ERROR
4. REPORT_FATAL : wrapper for SC_REPORT_FATAL

SC_REPORT_* macros is standard macros in systemC. But the macros is
uncomfortable because always the inputs are const char* format. So, I
made the alternative wrapper functions.

The inputs format of the functions are (string log_id, fmt, ...) and
(string log_id, string msg). The first format can support the printf
style. If you use REPORT_INFO(log_id, "Foo : %d", foo), "Foo : 12" is
written on the log file. The second format just writes the msg string to
the log file.