logger module first version

Just provide print_record() method to log informations.
logger.h and logger_main.c are the main file of the module.
mmap.c handles how to map the page in kernel out to user space.
log_util.h is a helper file.
logger_pro.c is the code of userspace program to log info into file.

Bugs:
- When unmmap(), there may be a bug warning in the kernel log, but it seems to be fine.