backup text file has custom name

prior update: -making DRY code -adding comments

done so far:
6.6.2014: lines 34-48 added backup Folder, lines 145-147 get last entry without array
8.6.2014: shortening the code, deleting unnecessary lines of code (lines: 34-40, 118, 121) , adding comments to all methods, lines 41-47 text file now has custom name (creation time) and is saved correctly to the backup folder.