move every files in the root directory

That way I can use git clone directly to download the applet in the applets directory (`~/.local/share/cinnamon/applets`)
`cd ~/.local/share/cinnamon/applets
git clone git://github.com/gfreeau/cinnamon-pomodoro.git pomodoro@gregfreeman.org`

Previously the pomodorro applet directory was contained into an other directory, that makes the applet undetectable in the applets directory (`~/.local/share/cinnamon/applets`)