Wrong log reading fixed.Non-ASCII support added

Method to read log file has been changed to support Non-ASCII characters. 
When using 
if log.find('substring') != -1:
instead of 
if log.read().find("substring") != -1:

reading log-file which contains Non-Ascii characters works fine. Also, 
f = open(log_file_path)
log = mmap.mmap(f.fileno(), 0, access=mmap.ACCESS_READ)

is used instead of
log = open(log_file_path,"r")