DB Basic Implement
Mem DB Architecture implementation is done.

Todo : File DB,....,

Todo : Define rule about Meaningful, URL DB.
Changed project default encoding(to UTF-8).
Completed MemDB
intermediate result.  Will complete upon the completion of DB package.
Merge remote-tracking branch 'origin/ImplementingChecker' into ImplementingDCD
Merge remote-tracking branch 'origin/ImplementingDB' into ImplementingDCD
Merge from DB, Checker