log file analysis improvments

major changes:
1. detailed error keywords
2. check 3 log files in the same round; if any error occurs, return
error
copy-to-history strategy improvement

I've tried to copy all last round folders to a history folder like
'timebofore220012122013', actually it did it, but I found everytime
round1 fold is missing and only the log were copied.
So I changes a little, mkdir before move log dir into it, by check it
first.