Add target folder of compiled objects

Add target folder of compiled objects and this will make the life easier for those who use vim/emacs + make.
Add a restriction for the note book title

If the title starts with a '.', in linux this note book will be hidden and the notes in this note book will not display, so I add a restriction for the note book title.
Merge pull request #6 from magl22/master

I add something to .pro file and killed a little bug